Yeah, that's not quite gonna work... Way easier to just get a spare set of linegear orbital gaskets and cut them down to make them a circle. That worked pretty well! May not be pretty but nobody sees it anyway and it has been very functional for me.Regarding the rubbers to retain the lenses, could you just melt rubber/wax then do a quick dab on the tip of the screw?
p.s. Yeah I know it's a ghetto fabulous mod.