Doctor,
Most of the North American 1-11s did end up as biz jets (in fact the few still around in the US are). The problem was the very noisy (& thirsty) Spey engines. Dee Howard did convert one to Tays and, from the video I saw shot by an FTE on the program, the noise was much reduced. I often wonder what a 1-11 would be like with BRR 710s or CF-34s - it would probably give a EMB-190 a run for its money.
The design rights were last held by Romaero but I've no idea what happened to them - or the fuselages left on the line in Bucharest. If you do a search in Yahoo Groups there's quite an active site that supports the preserved 400 Series at Hurn and also has most of the news of the type. Latest is that the Omani Air Force, which operates two Type GD (475 Freighter) versions, are looking to replace them with A320s.