Traditional brown oil resistent paper type gasket to fit on the base of 500cc OHV barrels. Also can be used for some SOHC Models.
As you can see from the profile in the photograph, these brown paper gaskets are made with the correct profile for early - late 1950's type OHV barrels. However it is also possible to fit them to SOHC barrels, but they may just require a small amount of 'tweaking' with sharp scissors (depending what type of SOHC barrel you are intending to fit them too).
As there were various OHV and SOHC barrels - it is also important to check any oil drain/feed holes on the barrel match up with the gasket (but again these can be quickly modified or cut with a punch or sharp pair of scissors).
Note that we also sell another cylinder base gasket - 0917, which is a different, slightly thicker oil resistent material, as an alternative to this one - but both are professionally made gaskets by the same manufaturer.
These gaskets are manufactured for us by a specialist UK gasket manufacturer
Final point 2020: I am also considering having another cylinder base gasket made, with the slightly different SOHC profile (i.e. single vertical tube in centre and open stud corners which original SOHC postwar gaskets had - but in the meantime this gasket and 0917 are alternatives)