The TVRCC regional meeting takes place on the last Sunday of the month at the Victoria Inn, Roche. Generally a few Chimaeras around (must be a 400 in there somewhere). You just need to be careful of the time (summer 11.00, winter 12.00).
Feel free to email me as I have a good friend who owns my last 400 chim which is a very sorted car and I have a 500 griff so you could try both engines.