I am doing a valve job on my twin pq and noticed that the valve cover gaskets that were on it are really nice metal/rubber gaskets and the merc ones i got from the dealer are just regular.....thick black paper/rubber ones that are flimsey. The old ones almost look like they are reusable and they are gray in color...Are these maybe aftermarket gaskets and should i try to reuse them or use the replacments?? Thanks!

Mine on my '94 7.4L were exactly like that. I've reused similar gaskets on cars, so I did with those also. No issues at all.

they sure look like nice reusables, if more people will chime in, im probably gonna reuse them.

You have factory gaskets and they are re-usable.