Try Grove Components. Run by Marting Williamson and his wife.
Has built several cars including an MG1300 to concours and currently a custom MGB GT.
A throughly good man who is an expert in mechanical lubrication by day and a brilliant engineer at the weekends.
Another vote for testing the horns. I was so convinced that the electrickery of relays and clock springs were to blame until I did check the horns themselves. Both had failed and a pair from Darren sorted it.
The only irritation is that the horn contacts are tiny.
RAC want £145 for my 2005 TF for a week in France. (With a clause that the cost of recovery does not exceed the market value).
What do others on here do for recovery?