The original RAE 1-11s were 400 & 200 series IIRC - I worked on both the Avionics test one (Type AK/D?) and the BLEU one (an ex-BUA Type AC which, perversly, was rumoured to fly 3 degrees off unles it was rigged offset - the product of a heavy landing). The current EPTS one is a 500 series I beleive and it's still active - the last item in "Flight" was as a stand-in UAV. There is a 1-11 group on yahoo that sometimes has almost minute by minute updates on movements in & around Hurn.
Rumors on this side of the pond is that the N-G fleet will be replaced soon by other T-tailed aircraft with CF34 engines.