Great craftmanship! I hope you don't mind/take offence on some comments though, as especially the torpedoes for the Bronco Seehund-model has several flaws (I have seen this on other posts of that model, so it's obviously a probelm with the manufacturer).
The Seehund used G7e(TIIIc) and G7e(TIIIe) torpedoes, and there shouldn't be any exterior differencies from the other G7e variants.
The most obvious fault is the propellers (it had 2x2-blade propellers, and I also think they appear too large on the model).
The battery- and gyroscopehatches only have one centre-bolt for fastening, and no rivets. A lot of other details of the hull is wrong as well, but that should be obvious by looking at G7e-photos available online, so I'm not gonna elaborate.
Pistol: Compare to my avatar.
The torpedoes are wrongly mounted to the sub: The guiding knobs on top should be in the rail alongside the submarine's hull.
Colours: The torpedoes used in the german submarines were unpainted steel, covered witha protecting layer of dark grease (probably a dark/transparent brownish colour - I have yet to find any valid documentation that give exact details on this matter). Torpedoes used for the K-Verband midget subs were most likely painted for camouflage reasons (they were moved on road and deployed a distance from the sea before launches). Most likely a grey colour.
The warheads were dark or light grey (for the Ka/Kb heads on the relevant torpedoes, most likely light grey). Exerciseheads were painted red and white (horisontal stripes/fields).
For more details regarding colour etc, check this thread:
http://models.rokket.biz/index.php?topic=407.0For modelbuilders, it's also worth mentioning that the ingolin-powered G7ut(TXIII) K-Butt torpedo was ready for operational use with the Seehund in april 1945, but was never fielded.
Similar, a planned version of the G7a(TI), the G7a(TXIV), never saw operational use with the Seehund (probably no exterior differences between those two torpedoes, as the modifications consisted of increased buoyancy).
The Seehund operated in more "open waters" than the other midget subs, so I think it's correct to omitt netcutters from the torpedoes on this model. However, for the Biber and Neger/Marders I think most torpedoes would have been equipped with netcutters on the head and aftsection (for penetreting torpedonets). Such torpedoes would of course also have the Pi1c or Pi2c pistols (without whiskers).
For Neger and Marder models/torpedoes: There is no reason to paint the batterysection in other colour than the aftsection - it's the same material.