Yes, you'll need an adaptor.
The fake silencer pinned/welded to the Beretta 70/71's were strictly to earn enough points to be importable after 1968.
The internets say that the Mossad used them:
https://www.tactical-life.com/firear...mossad-22-lrs/ in the '60's and '70's.
"Mossad issue" is not unlike "CIA issue", usually 90% myth, 10% fact.
That aside, the fake silencer in my eyes is probably not far off from what may have been used. An authentic silencer would be a '60's era design. Probably steel, painted and heavy. It may also have used wipes instead of baffles.
__________________
Need a FFL in Dallas/Plano/Allen/Frisco/McKinney ? Just EMAIL me. $20 transfers ($10 for CHL, active military,police,fire or schoolteachers)
Plano, Texas...........the Gun Nut Capitol of Gun Culture, USA
https://www.youtube.com/watch?v=pELwCqz2JfE