2008 S6 3rd Manifold

Been a while since i’ve posted, turned 200k miles this week. JHM ecu/tcu tune, exhaust, balancer, rotors, spacers. It think without those mods, i would not have kept the car.
I’m looking at going on my 3rd manifold, need TC replaced (this has been throwing a code for over a year), shocks need replacing. Most everything else has been replaced, and it’s been running ok, but for the usual oil leaks and wiring issues.

Have a local shop that can take care of the TC, but the cost of oem manifold is over $3500, and can’t find any Pierburgs. I love the car, but not putting out $3500 at this point in the game. I’ll be taking my old manifold apart next week and hopefully I can salvage the flaps and make a temporary replacement. Anyone have any tips on gluing the flaps? What did you use to reseal the manifold?