The HRC7113 "TruGear" was the gear drive version of Honda wide-area commercial mower. The transmission was made by the Auburn company and the chassis/deck was based on a Bunton Company design. Honda provided overall project design, engine, specifications, marketing and support after the sale. Sadly, the HRC7113 was introduced right about the time ZTR models were taking off in the commercial market.
Did you actually buy these from a Honda dealer? If so, they probably still have warranty. If you'll share the frame serial number(s) with me, I can check, The frame serial number is in the form of "MZCK-1234567" and is located on the rear of the engine bed.