I called a buddy of mine at a lawn and garden shop- he gave me the skinny on the 29cc-
says it is a half crank engine- says it reminds him of a cross between a ryobi 31cc two stroke and a honda GX31.
It has a backplate like the 31cc- so it would be easy to mount on a firewall- but the oil plug is in the backplate- so there would have to be a cutout or spacer for it. It has a cam/valve assembly similar to the honda- but unlike the honda, has a removable cylinder. The the pull start is integrated into the trimmer cover and the PTO end is similar- if not identical to a long shaft Ryobi with a clutch.
He couldn't comment on the power of it.
This may be worth looking into.