I haven't done this yet, so I don't know how many attachment points can be accessed, BUT...
You could, in theory, wire all the pulleys together (while still being able to r & r the belt) so they can't move when the old belt comes off.
Look at what's there, any threaded holes in the block that could accept a bolt as an attachment point?
Get creative, post lots of pics...hope it goes well from here on...