Re: Steering wheel vibrations. Spider twin spark.
Watch out for the road surface too its not unusual for a new surface to have small undulations in which at pressures like 39lb feel like wheel balance issues.
I'd also check the suspension joints and take it for a motorway run and see what it does at different speeds.
If the wheels are true and properly balanced I suspect that if its worse with increased pressures and there is no difference at speed that you may be looking at steering/suspension play.