you don't want the 2 pc, you want the metal gasket with the rubber gasket vulcanized onto it..
originally they had just the rubber gasket, fairly stout not bad, chemical resistant
however after torquing on the bolts so right the metal on pump plate and the tank begins to warp, gasket doesn't fit as well, so instead of engineering a thicker wider better fitting gasket they developed a metal ring, apparently to give it stoutness? so the gasket fits better..
then they realized meh, a lil better but not a complete fix so they vulcanized a gasket onto the steel plate, works a lil better not 100%
the one I got recently has a narrow gasket area, as in the gasket get real thin and narrow on one area.. so of course it leaked there, and they only go on one way so i took it apart and did some flattening, that's your best bet there, get that surface area FLAT, specially round the bolt hole areas where it tends to dimple..
do that, get the vulcanized gasket, clean, torque is important as well, that's where everyone got in trouble IMHO, they would get a leak from an improperly installed or worn out gasket then just try to old "torque that sucker down trick" then the pump plate dimples and on and on... so get it flat, new gasket then torque to proper spec, if it still leaks but not much, use some gasket sealer, the black pliable chemical heat resistant stuff, should work, i actually used an orange worked well till I got the vulcanized gasket but flatten the metal yields best results in my experience, I done a few