hello russ, hows it going?!
to be honest i'd say the only way to check for sure if its low pressure would be to fit a gauge. most engines are tappety on start up especially old ones like ours! but it could be worth taking the sump off and checking the oil pick up for any blockages or crap swilling around, flush it through first, then re-fill with vw synta silver oil and a genuine filter. get both from gsf for about £16. this oil is designed for these engines and as many people on here will tell you it just seems to work better than other stuff.......... for the price you can't argue!