Not sure if it is really worth it, but if you have time and opportunity...
I'd unscrew the low oil pressure sensor and tap the manometer there. That's what they do on Renault engines. Unless you have other, easier access?
My Fiats have two possible connections on the oil filter support, but that looks like a very last minute thing.
If you were living nearby I'd make you try another oil type, but I don't think it's worth the cost.