Need some guidence please.

Bought A 10k mile engine (supposed), i am suffering low oil pressure on tick over when hot.

900rpm Tickover 10PSI
2000rpm 32PSI
3000 rpm 45PSI
4000rpm 55PSI

Getting no oil light flicker on tick over so will check the sender but if it is reading right i take it it is a bad problem

I know issues could be weak pump or worn shells, the strainer was new so i doubt it is blocked as i have only riven 20 miles and have had this since doing the build.

Any suggestions on the pressure, best thing to tackle next.

I use 15w-50w Mobil 1 as i guess that will be everyones first question, and i also use breather kit and a big wing sump holding 9 litres.