No, I don't believe they interchange though I've never tried to. The mounts are different. Both loaders have a full sub frame that wraps around the tractor and integrates into the front brush guard and both loaders have a remote control station but both tractors have cabs.
The 9's upper mounts are closer to the cab than the 105's I think because the 105's exhaust pipe runs up the right side of the cab whereas the 9's exhaust pipe comes out of the hood (like yours).
I should see if they would interchange sometime. Been years since I dismounted either. Have no reason to remove the loaders. Both have Bobcat style quick detach plates on them and all my front mount stuff is Bobcat style so nothing is hanging out front except the loader arms.
Both tractors are pretty equal in breakout and lift capacity. I run the cast weights (1700 pounds a pair) on the 9 and nothing on the 105. Both easily pick up a ton or better on the pallet forks and 4x6 rounds on the bale spear. Never felt under powered on either. Both will lift the rear tires off the ground (and cause a pucker factor) if I'm not careful.
Always been partial to the M9 over the 105. Not sure why, It just 'feels better' to operate. The ergo's on the 105 are nicer as well as the view out the cab windows but not enough to sway my opinion. I think the 9's are better built and I was sad to see Kubota discontinue them. I actually have the last M9 with a Ultra Cab optioned out, that Kubota ever built. I waited almost 6 months for it from the time of initial order until delivery. It's optioned all the way, from dual speed PTO to creep gears, to 3 sets of remotes,flow control valve and a nice plaque that says it was built for me.....