I was regular at all the open meetings during the 70's, i remember him( Gally) on a RM for a minute, but never a Montesa,
in fact back in those days Montesa's were very rare ( in A grade) There was Ron Dinsdale and in Sydney Chris Kane rode one.
Other than those i did don't recall any others. Most people were on YZ's RM's , Maicos and Honds, even Kawasakis were far and few between.
The seventies was a sea of yellow. Decoster rode one overseas, Gunter rode one here.