You sure of your facts torres as I would have thought the -11 and -15 as found in the AT 402 would have preceded the -34 by a fair margin.
The AG designator refers only to the air filtration system fitted for Agricultural operations otherwise a -34 as fitted to an AT502 is identical to that fitted to a Bandit etc and as for running on Avgas, well yes you can but only for 150hrs between overhauls however diesel is fine..... older stuff caused sulphidation problems but diesel now has a reduced sulphur content which cured the problem and is cosiderably cheaper!
Other than that your probably right
Oh yeah BTW we have had the -65AG of 1250shp for a while now .