Thanks for all your comments and suggestions. All are appreciated. As an update, I have changed out the points, switched coils, and have gone back and forth on how the distributor sits.
So, back to basics, put back original (new) coil installed original points (also new). When doing so noted that the ground wire to the vacuum advance plate metal terminal end may have been in contact with the cam. (Not sure) but repositioned the wire terminal away from the cam. Removed number spark plug and replaced with a snug fitting wood tapered dowel. Cranked the starter. Plug blew out with a POP! Timing mark on vibration dampener just to right of TDC, and the rotor now points to approximately number wire on cap. Installed test lamp to negative coil terminal and ground. Turned engine clockwise with socket on dampener and watched the lamp go on and off as the distributor cam rotated. So far so good. I also had been having a problem with carbon fouling and ended up cleaning fouled spark plugs, thinking that the cause was a carburetor problem, but only recently discovered that the fouling had been due to incorrect spark plugs. Because of the fouling problem I thought that the combustion chamber would be carbon coated so I went online to search for combustion chamber cleaners. Bought a can of Liquid moly and put it in the gas tank. After running the engine fort a short time, it dieseled badly when turned off. Purchased a borescope. Saw that the top of the pistons coated with carbon, Went back to the internet. Found an article that recommended flooding the chamber with carburetor dipping cleaner. I followed the method outlined and used the bore scope to verify that most of the carbon was removed. Installed a new set of AC 437 spark plugs. Ran engine for a short time with no unsteady idle. I thought that my problem was solved, but no it was not, gone back to unsteady idle. So, I switched the carburetor from my 56 to the 55. The 56 idle is rock steady. The idle variation persists after the swap leading me to believe that the carburetor is not the problem. Now I have gone full circle and am right back where I started from. Bummer.
Happy

Thanks for all your comments and suggestions. All are appreciated. As an update, I have changed out the points, switched coils, and have gone back and forth on how the distributor sits. What has really been driving me nuts is the timing light flashing when the rotor is 180 degrees off and the timing mark is nowhere close to where it should be.
So, back to basics, put back original (new) coil installed original points (also new). When doing so noted that the ground wire to the vacuum advance plate metal terminal end may have been in contact with the cam. (Not sure) but repositioned the wire terminal away from the cam. Removed number spark plug and replaced with a snug fitting wood tapered dowel. Cranked the starter. Plug blew out with a POP! Timing mark on vibration dampener just to right of TDC, and the rotor now points to approximately number wire on cap. Installed test lamp to negative coil terminal and ground. Turned engine clockwise with socket on dampener and watched the lamp go on and off as the distributor cam rotated. So far so good. I also had been having a problem with carbon fouling and ended up cleaning fouled spark plugs, thinking that the cause was a carburetor problem, but only recently discovered that the fouling had been due to incorrect spark plugs. Because of the fouling problem I thought that the combustion chamber would be carbon coated so I went online to search for combustion chamber cleaners. Bought a can of Liquid moly and put it in the gas tank. After running the engine fort a short time, it dieseled badly when turned off. Purchased a borescope. Saw that the top of the pistons coated with carbon, Went back to the internet. Found an article that recommended flooding the chamber with carburetor dipping cleaner. I followed the method outlined and used the bore scope to verify that most of the carbon was removed. Installed a new set of AC 437 spark plugs. Ran engine for a short time last night, with no unsteady idle. I have yet to use a timing lite to ensure correct timing and adjust fuel mixture and idle speed.
Happy

You might try Ficken wiper service.
sales@wiperman.com

Happy

Try 3M 77 spray.
Happy

Yes, but now connected to proper manifold port. Thanks for the pics. You may recall during your visit that I have a running 56 400 that I have been using for reference while restoring the 55. The wiring order is correct, distributor orientation is the same. I have verified TDC and rotor positions are correct. With all this the RPM and timing mark on damper are unsteady. It is a puzzle.

Happy
For what it's Worth: when the engine was dissembled for rebuild (with less than 38,000 miles) number 7 piston had hole (burnt?) in the top compression ring grove. possible crossfire ?

Thanks for the feedback. High vacuum due to my using the wrong port. I plan to remove the distributor. I wish there were one of the old Sun machines near here but, they are almost nonexistent. Timing mark unsteady. moves +/- 5degres.

Happy

55 400 idle variations
With engine warm and the vacuum advance disconnected and the port plugged, idle is unsteady. A vacuum gage connected to the rear port of the carburetor reads max on the gauge. Visually comparing the distributor position to a 56 400 and firing order are the same. The 56 idle is smooth and vacuum is normal. I am at a loss as to what could be causing this unsteady idle, and high vacuum. Any suggestions as always would be deeply appreciated.
Happy

Many thanks:
Vielen dank
Bardzo dziekuje
Merci beaucoup
Muchas gracias

Happy

Yes. Thanks, I would like them. I don't do pay pal. but can send a check.
Happy

Thanks for the interest and feedback. I thought that I had a picture of the clip but could not locate it. Thanks for the posting. Before going the glue route, I will remove the passenger’s side (single switch ) and see how it compares to the posted photos. I am thinking that steel strapping might work if I can anneal it, shape it, and reharden it.

Happy