[Laird Scooby]

I suspect someone has played with the mixture adjusting screw on the fuel distributor to keep it running due to the clogging injectors. Also check the cold start injector isn't staying on past 8 seconds as that will flood the engine.

Bear in mind it could be burning off previous excess fuel from aborted start attempts.

As a first "go/no-go" test of the cold start injector, i would suggest getting it started from cold then pulling the plug off the cold start injector - squeeze the wire clip and pull the plug away from the injector at the same time.

If you locate the mixture screw on the fuel distributor, use an Allen key to make the mixture leaner once it's warmed up a bit until it sounds "happiest" once hot and idling. Bit of a Heath-Robinson method but should get you to a paoint where you are able to adjust the mixture in the MoT bay. Once you've done that, reconnecting the cold start injector plug will show whether it has a permanent feed or not, if it does, a quick solution would be to install a pushbutton switch on the cabin that you can press for cold starts and release once running.

I am guessing the important bit here is to get it MoT'd/drivable so while these methods aren't ideal, they will get you up and running and the rest can be sorted properly after you have that vital bit of paper from the MoT station.