A slightly better version of the Flight HP.127 image and a 3-view comparison between the Dart Herald and HP.127 Jet Herald proposal.
The nose section of the top view was distorted/missing in the original. I've ghosted in the revised nose but this shape is speculative.
http://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201909.html
http://www.flightglobal.com/pdfarchive/view/1962/1962%20-%202120.html
HP.127 Jet Herald Flight 6 Sept 62, 2 x 8850 lb st RR RB.183/1 Spey Juniors. Fuselage lengthened by 11 ft (3 seat rows), span reduced by almost 15 ft, area by 100 sq ft. MTOW 53,000 lb, cruise 455 mph, 4-abreast seating (44 to 70 pax depending on pitch), range with max payload (16,000 lb) 1050 miles, 1770 miles with 44 pax. Planned for 1965 if orders for 20 appeared before end of 1962.
Bifurcated intakes, main undercarriage retracts forward. "military beaver-tail rear door" as a future option. Field performance the same as Dart Herald due to greater engine power.