My Reillo burner 'mectron 5M type 161 T12 has stopped working. ?

My Reillo burner 'mectron 5M type 161 T12 has stopped working. I believe it may be that the fuel pump has failed.
How can I check or confirm that this is the problem. I have an old model Reillo burner(thermostat inoperative & different wiring) which works just fine so no problem with fuel supply or electrics as they are interchangeable. I have checked every thing else that I can think of.
Any ideas