Yep, I'd try oiler - the feed for the pressure gauge is integral with the oiler.
Phil, it looks as if you've already dealt with replacing the oiler in an earlier post - just wanted to make sure I fully understood how you removed the oiler. It seems that you took everything out and just connected the existing pressure gauge directly to the engine with the braided pipe - is that correct ?
Rob
Yes - removed all the oiler pipework and plunger, and just a length of 6ft braided hose from the engine block to the oil pressure guage (going through the 'plunger' hole via a big grommet). Replaced the fittings on top of the kingpins with grease nipples (just to keep the much out, I don't grease the tops).
This thread has all the relevant sizes
Oiler Removal
