As for the vacuum diagrams... find a factory service manual or a junk yard to go looking. but someone around here is sure to have pictures or diagrams. All of the screws for the bezel are on the back, real fun to take out. but again find a local junk yard and look for a 73-76 a-body it will most likely still have the bezel unless someone was really determined to get it.
oh and welcome to FABO! :salut: