I've now assisted my second friend within a month in getting their first Omegas (YAY!). The most recent one is this f300, ref 198.020 and it is missing the caseback gasket. I have part number 088.0607 for the gasket but it's proving difficult to source. I'm curious if anybody has the dimensions for this gasket instead, inside diameter and cross section (ex. 30mm ID x 1mm) so I may source a generic piece? Thank you! Yes, I know, pic or it didn't happen.