Can anyone ID/date this old 4spd trans

[caschnd1]

I have an old big twin 4spd on the shelf in the garage. Yesterday I tore it open and threw everything in the parts cleaner. It looks like the case, kicker cover, and kicker arm are all the same vintage. It's definitely old style (one piece kick arm and kick arm shaft) and the rounded kicker cover. Someone replaced the top with a ratchet lid at some point. It's covered in anchient goo so I won't know everything until I pull it out of the parts cleaner and get all the crud and layers of old paint off it. What I could find is a casting number on kicker cover "L 6" and a similar casting number on the bottom of the case also "L 6". Also on the bottom of the case was a series of numbers that were stamped in the case after casting and machining the area that mates with the trans plate. These numbers were "12 1 35". It looks like a date stamp, but I'm not aware of Harley ever doing this. I was told by the previous owner that this transmission came out of a 1936 EL, but I've always been skeptical. I figure maybe he jumped to that conclusion when he saw the numbers stamped on the bottom. Anybody here know about these things?
I'll try to post some pictures when things are cleaned up.

[48moon]

My understanding of HD casting dates is that the letter represents the month and the number represents the year. Your "L" should stand for "Dec." but guess the "6" could be 36', 46' or 56'.
You can narrow down the decade by details of the kicker cover and case. The Palmer book (pages 282-284) gives all the specifics you could want about them.

Good luck.

[Cotten]

No doubt '36s were unique in some way, but meanwhile, we need to know if there is a vent on the case on top near the kicker cover,... or just a flat spot for one,..or nothing at all.

[mbskeam]

hello,

how many mount bolts on bottom? I recall reading that 36 had only the 4 mount studs and did not have the mount , support under the kicker side. This is how the later ones are.
5 mount points in all on latter models
mbskeam

[caschnd1]

Mbskeam, I've got 5 mount points. 4 studs and the mount point next to the kicker cover.

[Cotten]

It's really hard to tell from the pic,.. black paint, etc., but it does not appear that there is any vent, nor unmachined boss for one. I think Palmers' spec's that as '39 and earlier, although its foolish to trust my memory.

[caschnd1]

Thanks Cotton, Mbskeam, and 48moon for your replies. I need to get a copy of Palmer's and do some more research. Anyway, it sounds like this trans is better suited for someone doing a correct restoration.