possible rear engine seal leaking oil

[VBMWMO]

Well I just took the ole R65 for a little ride and the oil leak at the oil pressure sending unit seems to be fine but there still seems to be oil
running down the back of the oil pan from the shelf below the transmission. At first I thought it might be the neutral switch but it doesn't seem to have any fresh oil on it. There has been so much oil
running down the back area from the little shelf that the oil pan gasket
is black and somewhat swollen at the back and a little on the left side.
It has always looked a little oily on top of the shelf area but I didn't ever
see it run down the back under the spacer bolt and I think it might also
be the rear engine mount. I asked the service manager how much it might cost to install a new rear seal bearing and also replace the "O" ring
at the oil pump and he said approximately $500 and that is if the clutch
is alright and if it needs replacing it could run about $1000. Does this
sound about right or do most of you just do the work yourselves and save
the labor cost? I checked the dipstick reading and it didn't seem any lower but I guess just a little oil will make a mess. I tried to smell the
oil to see if it could be transmission oil but I have had several sinus surgeries and I can't always smell things unless there is a strong odor.

Thanks for all your help