I have heard in Vacuum Pump shutdown systems, which I have in my 240D, oil gets pst the Vacuum Pump diaphragm. is this possible?How do I confirm this?

Also if my piston bores are that bad, I think I would have to
(a) both resleeve and rering or
(b) replace old pistons with new pistons, rebore , and replace rings
either way, this is expensive and would run maybe $1000 I am thinking. Is this a correct estimate? The engine disassembly and reassembly would be done by me, but machine shop time obviously wouldnt.
In that case maybe I would start checking auctions and papers for another Car.......