hi,nice rig,i really love how mac gear performs with klipsch speakers,the mc252 you have is an amazing amp,i liked mine so much i ended up buying 2 of them.
a good tube pre that will match up with your mc252 really well is a mcintosh c-20,your dust cap dilema is a super easy fix,get a shop vac & use your hand cupped in a circle to make contact with the dust cap then place the shop vac wand to your hand,it takes a few tries but it will pop right out every time.
good luck,mike.
