Very late to the party (as usual...) I just had a thought I wanted to throw out there.
My best understanding of the data sheet is that the 555 contact form is really just the 500 contacts with two bends in them in the right place. The difference between the -201 and -202 mounting options appears to be that the 202 has mounting lugs with holes in them, and 201 has no lugs.
In other words, for someone who enjoyed this kind of mechanical work... making a little jig to put the bends in the right places in the pins, and cutting off the mounting lugs neat and tidy, probably wouldn't be terribly difficult to do.
On the other hand, for someone who doesn't do that kind of thing or doesn't like it or otherwise objects... maybe not!
The 346-080-500-202 parts are non-stocked, but apparently can be obtained with a certain amount of patience and effort; I think DigiKey wanted a 25 piece minimum order, Mouser seems okay with an order of 1.
Donl