Your story sounds very familiar Anthony! I started modelling in the '80's and modelling life was easier then: less choice! If the local modelling shop didn't have it: no worries and buy something else. Besides the Revell, Monogram and later Italeri- kits I bought a lot of Heller 1/48 (-ish) helicopter kits and now regret not having bought even more of them… Those kits were and still are perfect to me: sparse but sufficient detail, not too many parts, not too expensive, and after having built some of them, I started detailing them; more parts in the rotor head, adding a panel line here and there, configuring the landing gear etc.
About the Seasprite and the Dauphin: I guess Tank summed it up nicely in his reply. I built the KH Seasprite some time ago. It was a lot of work; I could stil remember the Matchbox 1/48 Seasprite which I finished in a fraction of the time the KH kit needs. I remember the KH Seasprite nose is constructed of four parts, which makes construction sadistic hell and unnecessary complicated imho. The interior lacks an operator station, which would clearly be missing if you model it with the sliding door in opened position.
The Dauphin needs some surgery in the beginning of the build or else you won't be able to fit the cockpit in the fuselage halves: you need to cut off some of the rear cabin floor or else it won't fit between the rear landing gear wells. The kit builds up from the interior to the outside, which again imho unnecessary complicates things. Generally imho the KH- Dauphin suffers from too much panel detail. In real life, the Dauphin is a sleek, beautifully streamlined machine, and the separate door parts and fuselage panels on the KH kit make the model look more like a WWII- tank. It took me ages to sand out the overdone panel lines and get the fuselage flush again.
After that, the KH- model looks more than ok and ofcourse definitely beats the Trumpeter 1/48 Dauphin.