Try this guy he’s in the USA but is very helpful
bob@rc-sub.com
They call him Bob Martin he can also be found on YouTube as the RC-Sub Guy

Regards

Pete

Patrick,
If you decide to build it, it will certainly be one hell of an endeavour.
Here are a few facts about that model that might be useful before you start looking for plans or drawings:


Construction of the studio miniature
The filming models were scratch-built studio miniatures, not kits.
Typical materials used included:
Wood frames and carved balsa
Fiberglass shells
Plastic sheet (styrene)
Brass and aluminum details
Automotive paint finishes
Many parts were handmade to give the futuristic 2060s look.
Size of the filming models
Several versions were built for different filming needs:
Type of Model Approx. Length Purpose
Hero model ~3–4 ft (90–120 cm) Close-up shots
Medium model ~2 ft General underwater scenes
Small miniatures ~12–18 in Wide shots or effects
Different models allowed the crew to film launch scenes, underwater cruising, and docking at Marineville.
😎

maybe the right direction
http://www.davidsissonmodels.co.uk/I%20want%20to%20build%20Stingray.htm
https://culttvman.com/main/paul-harrisons-stingray/