Arghh it all sounds like a bummer of a job. Even just re-gasket gooing the sump and cleaning inside was such a messy job. 2/10 do not want. I've booked it in for further inspection at a popular mechanic in a few days so hopefully I'll get better in depth feedback on the condition.
My oil pressure gauge usually just sits in between first increment and 4 and doesn't move even when revving. So either the gauge is broken or something else. I used to drive it a few times when the tractoring lasted ~10 secs, but now it just spends its days sitting around like a princess waiting for saviour in case I damage it further. I won't find much in the filter as I've changed it recently along with the oil change and have probably driven it ~60km since then.
I honestly hope it's the oil pump, but deep down there's that nagging voice saying "hah yeah right, prepare to bring lube for the asshole".