I thought I had better come back and report the outcome of this.
After discussing with Sam, I sent the ECU and key fobs to Abacus which were re programmed and sent back.
The workshop re fitted the ecu and and All's right with the world again. Thanks Abacus !
Well that's the readers digest version. The process took months because it initially got sent back by uk customs and then I was aprehensive of re sending by post so had a friend take it over. I finally got it installed a couple of weeks ago.