I believe it came from a Plymouth sedan. 

I'll try and post a picture, but it is straight if looking down on it from above.

The bulbs are listed as 6v 25/25w Ba15d #1000
The Ba15d indicates the socket style.
They fit in the original sockets, no modification needed.
They appear to be shorter in regards to the distance between the filament and the base. I had to extend them to the maximum distance to focus them properly.  I thought I might need a longer focusing screw, but I was able to focus it.
The shape of the bulb is different, but that doesn't seem to matter, except for the concern on focus adjustment.

Years ago I bought this tail light stalk from a Plymouth Club member.  It is a little different shape than the original 29U tail light stalk.  I used it for years for the right rear tail light. Can anyone tell me what year Plymouth it goes to?

I recently had my headlights rechromed.  I had the reflectors nickel plated and then sent them to Bill Atwood for his UVIRA coating. Bill still only charges $75 including return shipping.  I then installed 25 watt halogen bulbs from Bill Hirsch.  The first picture was taken with the lights off and a flash camera, while the second picture is with the headlights on.  They are much better than before.  The 25 watt bulbs draw about 4 amps each, which is about the same as the  30cp bulbs (#1000) I was using. The original equipped headlights had 21cp bulb with drew about 3 amps each.  Long ago I installed a voltage regulator in the generator and had the cutout converted to a diode with heat sink, both provided by Jim Peterson.

Chet,
My car is probably not correct in that regard, I think when I rebuilt the roof in 1974 i but it a little too low because I cannot use the small winder handle for my windshield.   Having said all that, mine is curved slightly over the rear side windows, it is about 2 inches in the center but about 2+3/8 to 2+1/2 on the ends.  But, i think my headliner is about 1/2 inches too low.
John

Ask to speak to Tom Hannaford when you call.  He had some made for or Plymouth's a while back. Be sure they have been modified to ensure the gear will not spin on the heb.

Vintage Auto Parts also lists them for 28-32 Plymouths for $198.75
http://www.vapinc.com/

The only way I know to change it is to pull the engine, remove the valves and oil pump and pull the camshaft out, then take it to a machine shop to carefully have it pulled off.  Stay with it, as it is hard to get behind the gear to remove it and the shop broke the bearing flange removing mine a few years back.

The brass mechanics are fine, but the aluminum face is damaged and the needle gets stuck on it.  You could have a new face made for it.

I have one old one left that was Jay Fishers.  The face needs restoration.

Chet,
Thanks!  Their 1/4-24 Pan head screw looks close!
One of mine popped off when I was installing my dash, liked to never found it in the garage!

I see part number H-2 on page 287. Is that the correct part?

Regarding the headlight plugs, the Ford plugs do not interchange.  However, you could use the Ford plugs if you also install Ford components in the headlight.
I was able to reuse my plug brass wire ends, but that was 40 years ago.
You might be able to solder them and make them work even if slightly damaged.

As I recall, each of the rear door hinges have one machine bolt through and two wood screws. 
For my machine screws, I set the nuts in place so they would not move with JB weld an a small nail or two, that way I can tighten them if ever needed, or even remove them if necessary.

Chet,
On the front doors the door hinge plates go between the metal face plate and the wood pillar. For this reason the wood pillar and body are recessed for the hinges.  The holes for the front hinges are threaded for machine screws.
I am out of town this week so cannot send a picture till next week.

Plymouth Bulletin No 256,  Vol 43, # 6, dated Sep-Oct 2002.  The article is, "Through a Glass Darkly", one of Edwin Sapp's many fine articles on 1929 Plymouths.