Pokey, I have looked and looked and searched even the most obscure sites and there really is little if any 125cc> history pre dating 1974 excepting trials and tar bunny stuff. Suzuk also had a few bikes entered in the ISDT of the 60's with decent results but I can't find sweet bugger all on those either. The 90's I posted I'd estimate to be about '68 or '69 The tank and decal styling is slightly reminicant of the RH67 or around that era. I'm also kinda leaning toward the models being pre or just on Pettersson days as the engine styling is 'sort of' like the really oldschool suzuki stuff before they had any outside influence.
I found this little snippit also that attracts my curiosity..
1969 Olle Pettersson comes in 3rd place in World Motocross Championship GP250 class series ranking. Kinjiro Yajima piloting an RA wins the All Japan Motocross Championship 125cc class title.
This taken directly from Suzuki Corp. Racing History. So the RA was around at least in Japan well before 1970. Now I just want to see the bikes

it seems they were also successfull at home before the Ole Pettersson CZ infuence..this taken from the same site. At least I have a few names to work with now..more than I had last night

1959 April The inaugural All Japan Motocross race. Kazuo Kubo wins both the 125cc and 250cc classes
VMX247, I've been os a few times and I know how it seems other nationalities seem to go out of there way for us 'Aussies'

I'll send the letter and wait for a reply and I sure hope they can spreak ingrish better than some of the ones I've met out here