Has anyone got one? Rocking horse p**, I know.
The modern mpi manifolds don't fit on the P75 head as the rubber seals are too big for the ports.

Do any other heads have the large inlet valves?

palio 1.2 mpi has same inlet, very uncommon in uk but you may have better luck finding one off a palio on foreign ebays which are generally a pretty good source of 2nd hand fiat parts.