Not Stihl, my apologies, but still muffler gasket related.
In relation to the Dolmar PS-64xx/73xx/79xx saw family. Dolmar is selling the SLR muffler gasket as a replacement for the non-SLR muffler gasket.
I didn't know that and bought 5 to have on hand.
Once I compared the SLR muffler gaskets to the non-SLR muffler gasket I knew I wouldn't use them on my PS-6400/7300/7900.
Since I was in need of a gasket to get my PS-7300 going I made a couple myself.
I utilized a defective automotive cylinder head gasket, cut it to pieces with scissors, marked down the muffler bolt span and drilled two holes in each piece, bolted them together with a used OEM gasket on top, roughed the outer shape in on a grinder and formed the inner hole with a dremel type grinder and a diamond bur (didn't have carbide burs at the time).
I'm satisfied with the result, top left SLR muffler gasket, bottom left original non-SLR muffler gasket, on the right two home made gaskets in two thicknesses.
I have yet to see how my gasket will hold up on my PS-7300, so far it works good.
I have no liquid gasket maker at hand, I'd have to go find and purchase some.
P.S.:
The OEM gaskets have a steel core, mine do not.