any long bolt with the right threads will work. You don't need one that sticks up - and all you need to do is get it finger tight anyway.
the working end is 1 1/4" long, looks like coarse thread, either 5/32 or 3/16. I'd have to run out to the shop to figure that out exactly.
My DH says it might be something like a #6, or something, and that is a different scale then by the inch. At least we can expect it's standard and not metric.
I have an extra one (the one in the picture) but I may need it as I've got a White rotary coming in the mail, and I don't recall if it's got one with it or not. If I don't need it, I can send this one to you. The screw end is a bit worn, but it works fine.