Multico K1 Morticer Parts

[James_dean1986]

Bought an old rusted Multico K1 morticer. In releasing the chisel I have damaged the thread on this part and it now only goes back on half a turn.
The image is a little unclear but it is the collet that holds the chisel.
I cant seem to find any parts for this machine and was wondering if anyone can help. I would imagine this part has potentially been used on other Multico morticers.
Thanks

 

[James_dean1986]

Got some measurements if it helps.
ID thread 1 1/8 inch
ID collar 1 1/4 inch
OD 1 1/2 inch
Depth 3/4 inch