Hi guys: We had the same thoughts!
i bought one of these aftermarket inserts for a friend to relook a 1563 autavia a few months ago.
i asked this seller about rebuilding some 2446C bezels , sent him pictures with some words explaining that it was NOT inserts but MONOBLOC aluminium bezel blue/red or black anodized .
he didn't understand my request and answered me that this inserts would fit my bezels.......
i'm trying to find here in france some professionals who could help me rebuilding the whole aluminium bezel, anodizing and laser engraving for "tachy" , "MH" or "H" typo , successless for the moment.
one thing seems to be sure : the more you order , the less you pay.
for the gmt ones , if you look for some perfect result , this rebuilding must include a selective color anodization...hummm problem!
nos or mint spare bezels are scarce and expensive , that's why we sould try something IMO!
let's keep in touch...to be continued!
cheers!
ludovic