Trouble installing mulching kit on 36" Pro-Walk

I purchased a 36" Pro-Walk 2 years ago, and it came with the mulching baffle already installed. I took it off at the end of last year to put the bagging attachment on, and when I tried to re-install it this year I can't for the life of me get the side bolts to reach. See photo. The top two underside bolts are in place and tight. There's a little play if I push on it, but no matter how hard I push it won't reach over for me to make a connection on the side. It shouldn't be this hard.

What am I doing wrong, and do others have a hard time installing it? Is there an adapter plate I forgot I removed last year? If it didn't already come installed on the mower, I'd suspect it's the wrong size kit as I do know they make a 32" kit. I can't find any instructions anywhere, and the shop I purchased the mower from is no longer in business.

Looking for any help or advise. Right now I had to zip-tie it, and put duct tape on the gap.

One thing is that most mulch kit bolts should be left loose until all are installed. This allows some play when fitting tight parts.

Looks like it goes inside the deck rather than outside to me.

I think Darryl is on the right track, as there are no marks on the outside of the deck.

I know this is a different Gravely model, but check out the mulch kit on this machine at the 1:15 minute mark. It appears that's how they design their mulch kits, mounted interior.

https://www.youtube.com/watch?v=ZTYuGJA_jNo&t=77s