Looks like it's mostly there. The lift and mule. (Drive shaft? )
The tin tunnel cover seems to be missing and the chute rod and rear support.
Nothing that can't be made.
Ask for a better pix of the "mods"
As for will a 12 hp run it? Yes, but it will work it hard and you will be going slow.
I stopped using mine on my 12 for fear of doin it a damage.
If you are used to the WH
blower, this will not be as good. Flat out half the distance on throw. Oh, and I would say you need a 16 or better to run it well. My 19.9 will even bog down in heavier stuff.
As for a modified unit, that's max. I would be in the $80-100 mentally.