Running again.
Various hoses & cables refitted, new rocker cover gasket, top up the coolant ...nothing else left so time to fire it up.
Took a bit of coaxing & although it didn't need the choke, it didn't want to idle for a while. The hydraulic lifters were a bit noisy to start with until they'd pumped themselves up, but no repeat of the clunk, clunk, clunk of a bent pushrod. That's good then.
I ran it for 15 minutes or so until everything was properly warm, then shut it off & drained the oil. New oil filter & fresh oil, then time for a test drive.
Archie jumped in with me & we took it for a quick spin to the local petrol station, then back around the ring road. No nasty mechanical noises, but pretty hot in the cab & there's definitely a flat spot in the acceleration. Put your foot down & there's nothing, then it lurches forward. All or nothing. It's still all a bit brutal at the moment, no subtlety to it at all. You can't really cruise sedately in it -it's more a matter of pointing it in vaguely the right direction, stomping on the throttle & waiting for it to go
braaarrrppp.
So pushrod problem hopefully fixed.
I think I might get in touch with Tom Airey Tuning, the guy who tuned my last trike for me, for some rolling road time. It just needs to be a bit smoother & a bit more civilised, but it's getting there.