Just did a trial fit on the AT-6 with the irvine 25 MRKlll with A J Cs diesel head the hayes L A 25 mount is a perfect bolt up to the the sliding blind nuts in the X slot on the firewall the slimline 3216 compact pitts for the OS 32,35,40FP 25FX and 25SF is a bolt on fit with no alterations needed, side mount of course. The OS32 would be the same mounting but I have had the irvine sitting on shelf for 2 years of course an 1/8 ply firewall will be put over the original the the mount thru bolted. this will be no work at all compared to the beaver
I do have a head coming from Davis for the OS32 being the bolt pattern the same on the mounts both planes can wear either the ENYA 25 diesel. the OS 32 or the irvine 25
Most likely the OS will wind up in the beaver, but will fly first with the Enya ( since its already in ) If you go on the the Modelflight site down under they have the beaver listed and a short flight video as a stock electric I think flight time with this set up 10 minutes maybe, we should get at least 15 with the diesel

finallt the right pix at 6 irvine 25 coversion slimline pitts