Need help with replacement gasket

C chich

Hi gents, I'm looking to buy a lovely 176.007 and from the photos of the movement I've seen, it's in need of a new case back gasket. I've spent ages trying to Google the part number for it but to no avail. Couldn't find anything on CousinsUK and Ofrei is no help (comes up with an odd number OME-GAS-281-17). Would appreciate any assistance here, or a link to the right part on Cousins!