This is a Ikuzawa-Honda RS600DE in quite nice condition on eBay!
Bike: 1988 Ikuzawa-Honda (Harris Engineering) RS600DE
Location: Boyne City, Michigan
The seller states that this RS600DE is a one-owner bike, with the seller purchasing it from Ikuzawa himself. This bike has only been run four times on the track. The bike looks to be in very good, original, condition. However, brake fluid has been split by the front master and rear master causing some discoloration and paint peel. The rear swing-arm pinch bolts have also cracked the swing-arm on both sides. I imagine Harris Engineering could reproduce you a swing-arm if you were inclined to run the bike again. The seller states that this bike has only been run four times on track but also lists the mileage at 2k miles.
From what I can gather, the RS600DE is a parts bin bike with one-off bits where nothing OEM would fit. The frame is a Harris Engineering unit while the motor consists of a Honda XBR500 bottom end & head with a XL600R barrel and HRC cam. The rest of the bike is surprisingly sourced from a Suzuki RGV250, primarily, with the rear wheel assembly, front forks (The example on eBay shows conventional forks instead of USD units), front wheel and fairing (modified). See a data sheet here (This data looks to be based on a single while the bike in question is a twin).
We aren't privileged with many Harris specials on the open-market here in the U.S.A. but this one doesn't disappoint. The only issues are the two small cosmetic ones and the cracks on the rear swing-arm. The swing-arm issue could be resolved with a new one or, possibly, a repair depending on the integrity of those points.
Bid on this Ikuzawa-Honda on eBay .