I talked to a dealer in NJ area (Craiglist) last week. Search 'Craigslist All' - Honda 3813/4213. He had half dozen or so 2013/3813/4213/4514 in what he called his boneyard.
He said he was a Honda dealer. Thel telephone number is included in his listing.
At the time he didn't want to part out any of what he has. Wants to sell as parts tractors instead but he also didn't know exactly what he had so you might call him. He did say he had at least three new decks never taken out of the box for 3813,4213.
It makes no sense to me but people want to sell their whole units rather than take the time or strip off parts some of which are very easy to remove. A part or two will get as much as the whole tractor. For example a seller in Austin Texas will sell a complete 4514 without deck for a $100 but won't take any parts off of it and sell. I suppose eventually he will have it hauled off rather than part it out.
I could use a spare fuel pump, radiator, pto assembly, light assembly, ignition switch etc just to have for spares. But shipping is too expensive for a whole tractor from Austin Tx to Kansas.
FYI - there is a seller in KC who split a 4514 in half to use for a generator. If the mule drive is the same on it as on the 3813, he might pull it off and sell to you. Craigslist.
Another place to look for these is in huge pawn shops - I never realized the number of riding mowers that are parked in pawn shops that never get advertised.
I'm in need of the front pulley set up " mule drive" for my HT3813. Does anyone have one?