It's well worth someone picking up the design rights to the Hawker 125, with some 1500+still flying around and its structural integrity, they'll keep flying for decades hence.
As a (very) mature design the dispatch reliability for most other than the odd friday afternoon aircraft has been superb - that's why it's always been the best selling mid-size business jet all it's life, regardless of what Cessna or Lear or IAI/Gulfstream came up with.
The airframe and systems are indeed basic, but virtually indestructable - the legend is there forever about the Botswana 125 which had it's engine shot off by a sidewinder missile over angola whilst all essential systems remained in tact and the aircraft safely landed with a myriad of pipes coming out of the side and serious holes all over the cabin structure. It's the only jet I think that can still be flown with no electrical power up front at all. One could keep changing the engines and avionics periodically and the airframe would just keep going. The original design had a structural life well in excess of 100 years of intense, airline type utilisation. It is the proverbial brick out-house.
Someone could keep those flying for another 50 years with the tools and jigs to replace the odd component. Spares sales for a 1500 strong fleet of bullet-proof stand-up cabin, good range jets is going to reap tidy rewards for whoever picks that up.
One cannot say the same for the Premier and Hawker 4000 models however which are inevitably doomed and you'd be a brave person to take on the support of those.