Thanks - I’ll give them a shout. Word is from the Navion owners group in the US is that the FAA want something, anything fitted as there’s been a good number of walk away accidents where people died from head injuries.
The a/c is a Rangemaster H on the 2-Reg. I think she’s the only one in the UK - there’s a couple of model As and Bs on the N-reg. I’ve got some ideas for fixing points but you’re right, it isn’t straightforward..