Burton Pinto rebuild

[MikeV67]

Hello anyone who can help. New to PH and new to Pintos!
Have recently bought a Dax rush that has a Burton Pinto 2.1l engine, fast road cam and 4 motorcycle carbs (currently the limit of my knowledge)
Unfortunately have blown the engine (wasn't in a great state to start- somewhat missold on Car and Classic)
Have contacted Burton, but they no longer do rebuilds.
Thinking of 3 options:
a)Replace with a 2l Burton i have found but has little history (for sale at £1k)
b) get existing rebuilt (does anyone know of someone in the Surrey area?)
c) replace with a more modern/faster engine

Not looking to spend a fortune, have looked at a few sites that are offering exchange rebuilds at £3.5-£5k
Any thoughts/contact gratefully received!!!

[MikeV67]

Thank you for all your replies, will spend a bit of time contacting the above, everyone I've tried so far everyone is very busy, although one chap who could look at it in July reckons he could easily get 200bhp out of a rebuild.
@Peterg1955, thanks for the link and would take me back to my youth of rebuilding mini and beetle engines, unfortunately time and space an issue now! I'll have a read anyway..........

[MikeV67]

Thanks all, engine being stripped in a couple of weeks to see what would need doing. 2.5 duratec looks an interesting option if engine looks like it needs major work.