Matchbox's Twin Otter with the aerocraftmodels.com resin cockpit section, engine front and propellers and their brass undercarriage. I wish I had bought their wheels as well. The engine fronts and propellers are very subtly different, you could modify the Matchbox propellers fairly easily to be feathered, but the cockpit section gives the correct windscreen profile which makes a massive difference and the brass undercarriage is brilliant for a model that is quite heavy due to all the nose-weight added.
I believe the skis are hydraulically retractable on the original, but Matchbox moulded them with a solid piece under the wheels. I opted to open this out and raise the skis, which made the mounting on the undercarriage very difficult and insecure: not recommended. The kit was missing the transparent sprues when it was bought (seller was honest) so the side windows are Micro Krystal Klear. Xtracrylix Red Arrows Red and Mr Color gloss black make up the main colours, with Mr Color GX112 gloss varnish to finish. Decals are Caracal and were flawless; I just wish they had the 'Ice Cold Katy' script for the cockpit doors. The aircraft are very clean in all the on-line photos I could find, but exhaust staining streaks are really heavy on the original; although very prominent on the model they really aren't overdone.