Tailstock Mandrelsd for 12 Clausing Lathe

According to :

I doubt that it is any different from the one for the change-belt machines like mine.

MT-3 socket?

You could try making your own -- somewhat easier if you have a horizontal mill to cut the keyway in the bottom.

I recently saw someone who was making replacement tailstock rams for South Bend 9" machines (was that Marmachines?). Set up to make them, then start selling them on eBay once you get it right.

Good Luck, DoN.