Hmmm Tallsar...since when in the 1960-1970s did we ever base military orders on sustainable production ? I'll leave others to produce a list !
Instead I will comment on the proposed Type 191/193 naval variant ,which as the Belvedere picture on Albion shows ,was overly ambitious .However it was sized for the larger HMS Eagle class carrier lifts.As the picture shows there was a novel way of fitting the rotor blades if removed but the 191 had blade folding ,using chinese scaffolding I think to stow the rear set! Certainly I wouldnt have wanted to be working on them on deck in a sea state 5!
Three 191s were virtually completed when the contract was cancelled ,with a vee tail unit (fitted the lift better) and a Wasp type heavy duty landing gear.None were fitted with the intended Leonides Major piston engines and instead were used as Gazelle turbine engine and transmission test rigs for the Belvedere.One eventually ended up in the pit at Ternhill.
The similar Type 193 for the Canadian Navy was cancelled before any were completed and reallocated to the RAF order.Canada went for the CH-124 Sea King instead.
I admit that the whole 191-192 programme was financially a disaster,with all the investment lost , but in terms of keeping the UK at the head of the technology game and independent of foreign powers it was successful. Sadly its demise saw the breakup of a very good design and engineering team and although some of the specialism went to Yeovil to work on Lynx and future projects (including tilt rotors and tilt wings) the tandem rotor expertise withered away.