This is a drawing of the hood (top) bow dimensions for all of the 6 and 8 cylinder model "Sport" bodied Packards from 1922 until around the mid 1920's. Your Packard will not be exactly the same.

Very neat Karl. Why did Packard built these cars without any means of checking for low oil level. It could not have been a cost issue, beats me!

I fitted a permanent dipstick to my 1922 Single Six, which has the same oil level setup as your 143. The problem with using a stick in the oil filler is that it will hit the crankshaft. The solution in my case was to braze a copper guide tube, for the dipstick, to the underside of the oil filler, bent so that it avoided the crankshaft.
For the dip stick I used section of 3/32" dia straight spring wire flattened a little, on the oil level end, with a full mark. This was all done when the engine was apart for rebuild.
The difficulty with this solution in your case is bending the guide tube to miss the crankshaft, without having the engine apart. It may be possible to turn the engine by hand and achieve the same result by trial and error.

I assume you are referring to one of the gear change detent springs. The detent spring on the top gear selector on my 1929 633 was weak allowing it to slip out of gear. I bought some similar-looking springs from a hardware store and with a little experimentation with length and stiffness of the new spring, it no longer slipped out of gear, It's not critical part, too weak and it won't hold too strong and it will be harder to shift gears

It is almost certainly not Town Car Medium however finding a sample of that color will not be easy. As has been suggested you might get lucky by uncovering a part that has not been painted or finding an unrestored example, there will be one somewhere.

There is a 1922 Packard Single Six Sport model here in Australia that is believed to be essentially unrestored, it is very dark blue almost black.

I have bought color chips from this company, unfortunately the earliest Packard colors are 1929.autocolorlibrary.com/pages/1929-Packard.html

Good luck

Nice car but I doubt that it is an original color, the cars of that era tended to be painted much darker colors. The pigments for such a color may not have been available then.
I owned a 1922 Single Six for nearly 50 years and sold it recently. Great car, we took it on many long distance tours.

The original paint colors for the 1922-23 Packard Single Six cars are contained in the dealers facts book, issued by Packard. A copy can be viewed on this site.

Open the "Literature Archive" on the LHS of of the screen, click on "Sales and Dealer Info..." ,click on "Data Books", scroll down to "1922-23 Single Six 126-133...."
Page 24 gives the colors of the various parts of the cars. The body and wheels of the open cars were painted Town Car Blue medium striped with gold. The fenders were black. Brightwork was nickel, (chrome plating was not used on Packards until 1929.)

New owners could choose to have their cars painted other colors but this would not have happened often and probably only on the top of the range cars.

I did all of this so long ago I am struggling to remember the detail so hopefully, someone will correct any errors.
Timing the distributor.
Before disassembly turn the engine to TDC with # 1 cylinder on the compression stroke and note the direction of the rotor and distributor clamp location, then reassemble the cam gear and distributor drive shaft so the rotor and distributor are in the same position. Tighten the distributor clamp after rotating the distributor so that the points are just starting to open using a static timing light across the points and clamp. Final running adjustment is done by ear, a strobe light cannot be used because the timing mark is on the flywheel and only visible with the starter motor removed. Not one of Packard's better features!

I am guessing the 9th series generator is mounted the same way as the 6th series and earlier cars in which case the generator can be withdrawn without removing anything else. There is a heavy brass plate sandwiched between the generator and the engine, The generator drive gear is mounted on that brass plate. The generator drive shaft is splined to the generator gear. The generator can be removed by removing the three mounting nuts and leaving the brass plate in place without removing anything else. I have read that this cannot be done but I have done it a number of times without a problem. Re-engaging the generator spline with the drive gear when reassembling requires a little care but it is not difficult

Unfortunately, those illustrations, from a part book, are for a different and smaller model than Steve's 645