Dale, Re the crank handle - it was on e-bay and had the square hole on the end but it is no longer there--pulled or sold. I was surprised because all the other crank handles were as you describe. Part of me was hoping it was made for the easel and misidentified, but the listing did not have the square hole dimensions.
I have a bunch of tools from when I was in my 20's (way back when), but alas a welding kit is not one of those...
Jim, thanks for the socket tutorial. I bought that set back in 1980. I think I may have used it for my car 74, pre anti pollution (lots of room for a beginner to work with) Corolla as I couldn't afford to go to a mechanic while I was in school. I'll have to count the star points.
The square turn heads look to be hand made and vary very slightly in width along the shaft which has made it a guessing game, and my ignorance in socketry hasn't helped. lol I saw a universal socket, but thought it might be too wide for the space in between, but may measure and re look at that again.
Thanks to both of you for your suggestions. With your information, I will try again getting samples from the hardware store (and car parts store), and if that doesn't work, I know a blacksmith (and maybe he knows a welder) who might help.
I love this easel and am finally in a studio where I can use it. It needs a 12 foot minimum ceiling to be fully utilized at eye level by 5' 6" me. I stand when I work, and it's the first time I've been able to stand and work on the bottom of some of my larger paintings without having to Jerry rig an extension on my other easels that always had the potential of slipping and damaging the canvas.