Wanted Clarkson " S " Type collets

Forgive my ignorance, but I don't know the various Clarkson types.
I was fortunate to pick up second(?!)hand at one of BSMEE "bring and buy" sales, a small Morse2 Clarkson collet chuck, with just one collet! I picked up another collet at an ME show, and then made two more for myself! These are the older pattern, that has two parts of the base cut away to form the physical lock betwen the collet and its holder. They didn't prove difficult to make, since they were bored in the Clarkson itself. I made several blanks at the same time for future use. The only slight problem was the 20 tpi Whitworth TYPE thread inside, as this is a constant pitch regardless of diameter. At the time, I hadn't a suitable tap -( rare), and neither a small enough internal thread-cutting lathe tool. It was solved by using a UNC tap instead, which DID have the right pitch, even if not the right thread form! Its only a small mismatch to a Whit one! (Normal home tolerances prevailing!)
This old type of Clarkson collet does still turn up in ME-type shows, but increasingly expensive, even though secondhand. The later ones with only half the base cut away as used in some of the far-eastern chucks are more common, .
Dave.

Hi If you are in or near the Halifax area try RD Barrat small tools. I use them for quite a few secondhand tools. I dare say they would post them to you. Excellent value for money.
I am not part of or associated with Barrats nor on this occasion am I cynically trading.
Cheers
Dave