Best guess is it was canceled, the 35 Remington Handi was slated for production about a year ago, but the 35 Whelen pretty much preempted it as far as H&R/Remington is concerned, it was canceled after insufficient distributor preorders were placed, same thing that happened to the Handi-Mags in 2008.
If you really want a 35 Remington, get a 357mag accessory barrel fitted to an SB2 frame and have it rechambered by your gunsmith.
Tim