HI Owain
Opinions differ on what and where to use various gaskets and goo's
Take some time to flatten off the mating surfaces of any high spots,
Remove studs and flatten the areas surrounding the stud holes in alloy especially,
If you have not rebored the cylinders then I would not consider not using base gasket
lowering the cylinder that amount would mean the top rings would clout on any slight wear ridge in the bores
Not using gaskets may lead to clearance problems in some areas, especially plunger gearbox gear box selector mechanisms
I use gaskets and Hylomar (same as Wurth DP300)
Works for me
John