Rpm still not better

[1968 volvo]

Hi Volvo Nerds
I have a 1968 Volvo 142s with b20 engine and the suhs6 carbs. It idols at about 1300-1500rpm.
Here is the way that it acts.
-It idols high only when it warms up
-It only idols high only after you rev it
-It goes down to a reasonable rpm when in gear. (It has a BW35 transmission in it)
-It seems to be running rich but that could be the carburetors not being very well tuned

Here is what Ive tried to fix the problem
-I had the carburetors rebuilt by a gentleman by the name of Thomas Bryant (They needed to be rebuilt anyways)
-I replaced the carburetor to intake manifold gaskets
-I replaced to intake manifold to head gasket
-I removed the second set of butterfly valves in the intake manifold and plugged the holes
-I replaced all the vacuum hoses
-I replaced the one way valves for both the pcv and the brake booster
-I replaced the brake booster( I did this prior to trying to fix the rpm when I built the brakes back up)
-I made sure that the fuel pressure was in line with what the Haynes shop manual recommends by installing a fuel pressure regulator

I'm at my whits end and was wondering if anyone had other suggestions. I tried everything people recommended last time and I'm back for more.