I stand corrected he does have an internal key, Philip is in Sweden and has converted the engine over to run horizontal which is a feat in itself.
It's really not, especially on most V-twins since they generally have a pressurized oil system anyway and it's mostly a matter of relocating and securing the sump intake head.
For smaller engines like say the Flathead on your typical push mower... yes it's more involved but it's still something one can do and have back running in as little as an hour or two. What is a bigger PITA on those is mounting them to anything easily as a Horizontal shaft since you need to use the old mover deck as a motor mount or at least as a template to make motor mount tabs on whatever you're doing.
At least with the big Vtwins it's 4 bolts holding the engine down, and 4 more holding the heavy deck plate. Thats an easy graft, No weird shapes or oddball bolt patterns
What a project. I guess this is his contribution to going green for the planet, don't throw anything away just use your brain to figure out how to make it work.
Waste Not, Want Not. I am forever using a broken this to make that, or cutting up one thing to make a bracket or what ever for another.
My 208 has the Canadian oil cooler and check valve pancake block off a big Kohler twin. I initially cut out the sump feed port and used it as the remote oil filter mount but the filter stub threads were pretty rough and I ended up getting an actual remote block... which was for a diesel and had to see some modifications to work.
$28 and modify
Or
$180 direct fit
Modify wins every time
When I kick the bucket my daughter will need someone clever like that to keep this place going.
Let me get an ETA on that, I'll dig yer hole pop