Gearbox gasket/sealant for alloy gearbox

[56Lotus]

I'm after a recommendation for a good gasket sealant for an alloy gearbox. I'm running an old MGA gearbox in my Lotus and the front cover leaks into the bell housing. I've tried just the paper gasket and paper with Hylomar Blue but it still leaks and to change it is an entire engine out job. I think one issue is the cutch fork pivots are part of the cover and therefore the cover is put under strain when changing gear and this breaks the gasket seal?

I'm after a recommendation for a good, strong/flexible oil resistant gasket compound to use with or without the original paper gasket.

Thanks in advance

Jon Adams