There you go, a digital caliper will let you measure, with some accuracy,
the crown race seat and head tube ID.

Pro LBS should have a ream and face/ die set
to recut overlarge fork crown seats,
and undersize Head tube ID's.

Older Italian Steel frames, Famous names, shipped painted,
but expected each dealer to have the tools
to finish the thread cutting , chasing,
facing and reaming to assemble the bike.