Don't the (later) unit Triumph engines have an oil pressure gauge sticking out forward low on the rhs side of them ?
Seem to recall the thread is something odd, so you'd need an adapter.
You also need to know what pressure they are set for - 7 psi ??
Or they will false trigger all the time.
It may also be like a Guzzi, where the dealer commented that if the oil light comes on, its too late...
Which means Guzzi also have a pressure sensor - probably also with odd threads.