i have just recieved the following "correspondence" regarding parts for the aquastar benthos 500:

"About 2 month ago I bought on eBay a replacement and then realised that
there seem to be to types of Benthos 500 out there. One like on the
http://www.aquastar.ch website with a 43mm wide body and another one with a 40,5mm
wide body http://www.watchcat.com/NewListings/benth4252dvr.htm. The 40,5mm
version does not match in one single part the orgional one. Bezel and bezel
insert looked like origional but they were not. That was amazing. Some guys
out there sell the 40,5mm version in perfect condition as origional but I
guess they have replaced the whole case and just used the movement and all
other inner parts to make it look like origional. I cannot judge if the
40,5mm version is a fake but having had it in my hands I would guess that
someone did run a cheap replacement version some time ago. There are several
obvious differences. The origional bezel has no inner metal ring so the
bezel insert marks the end towards the glass the other one has an inner and
outer metal ring around the bezel insert. Ther some other obvious
differences but it is too long to tell you everything. You will realize when
you compare pictures.

I do not think that there will be replacement parts available for the
Benthos 500. Either you have bought a 100% one or you have to go with what
you have. To upgrade missing parts seems to be imossible"

any insights about what is described above are welcome

regards

itai