I have a boiler that some times just doesn't want to kick on,
With out just a little help (a tap from the back of a screw driver will do)
It looks like some kind of switch or control or something, it has what
Look like points that seem to make and break contact as I tap on this
Thing, then the circulation pump kicks on, then a few moments later
The boiler fires up, and then it works fine for another few weeks.
What is this part, is it specific to this boiler, is it commen, I guess
I just want to know if I'm going to have a problem with availability
Because this boiler almost 35yrs old

Sounds like a relay controlled by the thermostat. You are correct, that it could be hard to find an exact match. You should be able to find something that will work if you can identify the voltage and amperage ratings. Usually they have a 24 volt coil that the thermostat activates, and then contacts that need to handle the voltage and amperage of the pump. Usually all the info you need is right on the relay. Any place that sells furnace parts should be able to help.