Mine was built from scratch. The donor material came from a piece of junk I found out in the field on a ranch were I was working. So I started with a big piece of steel and whittled it down leaving extra material for the 1 and 2 am stage. Not an option for most people.
The other thing I can not remember how I did it, 40 + years ago!

Rick's will be interesting as it was a modified original and thus others could copy it.