The trunk lock tumbler and the ignition tumbler may not be identical but the code is the definitive way to make the proper key for both. Making it from the tumbler, it may fit that lock but not necessarily the other!

Case in point was in trying to get into the trunk of my 1965 Imperial after I moved it to my Oregon shop and the key was missing so I had a key made from the glove box lock. However, the glovebox lock has fewer tumblers than does the trunk lock so, while the proper key made from the code would fit both, the one made for the glovebox would fit only the glovebox. (Feeling a bit foolish, that was about when I realized that I could put a battery into the car and press the button for the electric trunk release!)

I have a reprint of the 1935-1941 parts book. Would that have what you need or have you checked the Literature section here to see if it’s available?

I also have a separate Clipper parts book.

With solid lifters, it must be a different engine than the one that should be in a Custom. As far as I know, the 356 that the car is supposed to have did not have solid lifters as an option.

Here's one you don't see every day: a 1937 Packard hearse with a Silver-Knightstown body! The site has page after page of Packards but I think it might be a brokerage that gleans the data from other sources.

The one in the link is for a senior model so won’t fit a 120.

Try SMS near Portland, OR as they seem to have about everything imaginable either original or reproduction.

Interesting the 1954’s Gear Start is called Twin Ultramatic!

Is the one RHD or was the photo somehow reversed?

As for factory A/C, two ways to tell without opening the hood are the outlets on top of the dash and the extra knob just to the left of the radio volume control. Under the hood, it would have the compressor on the left with the oil filter canister relocated to the right.

While waiting for an answer on the transmission itself, my smaller parts are links that will take you to my site where you can buy them.

I hope that someone here buys my former 1940 110 Club Sedan which I owned from 1966 or so to 2007! Otherwise I might be tempted and I am too old with too many other projects already to do it justice which is why I sold it in the first place.

I just remembered that it is still listed in the Sold section of my Packard / IMPERIAL page's Classified Ads! Lots of details that I had forgotten about.