Where can I find one of these or is there another solution short if
disassembly ?

Disassembly isn't that hard. The instructions are online at the Atlas/clausing
site; it's the only procedure they've posted for the MF mills.

See

http://www.atlas-press.com/tb_hmillbelt.htm

Your MFC should have two-step pulleys, not 3 used in some earlier machines.
When I did this I used a Gates Truflex 3290 (5L290) belt.

Pete