I believe 1957 - we always want pics!!

It could have, both dry and wet were available

In the 1950's and 60's both wet and dry clutches were available as well as direct electric start or pony start. I'd look at the parts books in the Library section and study the wet and dry clutch setups and see if you can't determine it from there. Both my D4's are dry clutch, can't tell you what to look for on a wet clutch from memory! I just posted a couple of D4 vids on YT, won't help you much, but may be interesting.