Front Brake Problem

[Trevor W]

My Harrison Cob76 has had front braking problems from the start.
Front left hand caliper locks skids wheel and releases
1. @ 60 km/h with hard sharp breaking
2. @ almost stopping say last 3 meter with medium braking from 40 km/h
Front R/H does not Lock
Regular in traffic braking no problems no pulling even with hands off Steering Wheel.
Components are
Calipers Commodore VT.
Booster Ford FX
Master Cyclinder New after market (Protex P10212)
Flexible lines - Braided
Plumbing Bundy Annealed
Connection to Master Cyclinder front Bottom to R/H Caliper Front Left connection to Left Caliper. Correction Attempts Swap pads L/H to R/H
Remove Caliper to Brake Prof, no faults. Remove L/H Disc checked out of true OK. Bled calipers many time when cold and warm.
Had Booster Serviced. Removed R/H Braided Line air purged into clean tissue no residues.
Last option I can think of is to reverse connection on Master Cyclinder I have been told won't help.
I have read many interesting Threads and answers over the years so if any one has experienced this type of problem and won I would be very pleased to hear.
Regards Trevor W