At this time a conversion had been successfully effected overseas, by Jack Riley of the USA. Jack Riley was written to; he came to Ceylon, had a look at the workshops and was satisfied that the work could be undertaken. He then sent the blueprints, together with new engines and upholstery etc. - but the main component was the drawings.
The conversion entailed the replacement of the Herons existing four Gypsy Queen MK30 engines, with AVCO Lycoming IO540 s - which were lighter in weight and more fuel efficient. The new engines also significantly increased power from (in approximate terms) 280hp to 340 - 360hp.
The 17-seater cabin was converted into two luxury compartments of four seats each with a jump seat for a steward. Heater cabinets were installed for storage of refreshments and a compact fully equipped toilet was introduced in the rear cabin.
All in all, a super luxury flying machine was produced by the Air Force over a quarter century ago!