Volkswagen: VW oil light and a/c, clutch works, service ports


Question
I just bought a 73 VW beetle model 111.  My family owned a 72 Super beetle in the past so this is not my first air cooled VW.

I am having 2 issues with it.

1.  After driving in the city for 15-20 minutes the oil light comes on when I am at idle.  As soon as I take off and get get moving the oil pressure goes up and the light is out.  Does this mean a thicker oil needs to be used or does the car have a leak somewhere?  I still have the oil which came in the car so I dunno what weight it is but it is new and clean on the dip.

2.  The car also has the dpd a/c system in it.  The compressor clutch works and so does the blower inside.  For fear of doing damage I have not yet tried to use the a/c to really cool the car.  I just switched it on a few seconds to see if the system was DOA or not.  Is there anyone who still makes parts compatible with dpd systems?  I speculate that the o-rings are all shot and the system is discharged.  BTW where are the high and low pressure service ports on the system?  What should the pressure be on each side?

The car has 32K miles on it, was garaged since day 1, and the only owner was a doctor's wife that rarely used it.  I think she was in her 40s when she bought it new in 1972.  It has not been hot rodded, modded, or abused from what I can tell.

Thanks for your help!

Answer
sadly this car is older than me, and i have very liottle personal knowledge of the aircooled engine. however i will ask a few people that have experience and knowledge of such items and get back in touch as soon as i find out. sorry i cannot be of assistance know, but i will try and find out for you. john dempsey.