Yeah the oil pressure should register faster upon start up.

It ought to register a bit lower after the oil is hot and at idle.
So maybe the oil pump is iffy.

Its good that you are observant !.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD