Series2 Brakes CB MS

I had a very good brake pedal up until I changed the leaking front wheel cylinders. I have bled the system many times now and happy all air is removed. The vehicle is a series 2 LWB with non Servo CB master cylinder. It has with 11" brakes all round.
With Front Twin leading shoes, with twin 1 1/4" wheel cylinders and
Single leading shoes on rear with single 1 1/4" rear wheel cylinders.
The problem is the pedal height is very low on the first press, and needs a quick pump to get a good pedal.
I've Increased pedal height off the floor to maximise recuperation of the Master Cylinder and adjusted the MC piston rod to eliminate nearly all free play. With all Brake adjusters clamping the drums tight, the pedal drop is still lower than ideal 1st pump and pumps up. With pipe clamps on all pipes the pedal is solid, but at a lower height than expected and It will still pump up higher.
The MC may need bleeding so drove up a 30 degree slope in a desperate attempt to improve the situation, wedged wood on the brakes overnight.... etc Can anyone suggest something to improve this? Would Smaller diameter wheel cylinders on the rear axel help to reduce fluid volume, and increase pedal height.

If it was fine before it will be something you have done, ie springs in the wrong place, something daft that we all have done before.

If the shoes are adjusted properly then there must be air in the system?

I've bled the system at the wheel cylinders and got all air out. I'm wondering if air could be trapped up in the master cylinder. Its the earlier CB type. I wedged the brake pedal down hard over night. There is no fluid loss.
In the morning the pedal hadn't changed, was solid but still to low on first pump. Like adjustment was needed.
The recuperation valve in the master cylinder would allow fluid to leak back? All adjusters work perfectly...