Hi, Kapt. Wolf. Glad to pass on any info I have gathered. I found the kit in very good condition upon arrival, nothing was broken and all parts fit together extremely well. The assembly of the two hull halves was a bit tricky due to its size. I used a lot of clips to hold them together at the keel. I used those little paperclips that you squeeze together to open. FYI they come in various sizes. After assembling the hull I put a bead of silicon caulk over the seams. Before you go beyond the hull assembly decide what you want to make functional: rotating guns, opening torpedo tubes, ejecting torpedos, lit up running lights (red/green) electric searchlight, rotating RDF antenna, a siren? How many motors, all three props to be powered? RC or not to RC? If you want to Rd the model, make a sketch where to locate the RC components.
I designed a mechanism to rotate the midships AA gun and will in the future so the same with the AFT gun. I used extra servos hooked into the rudder servo via a Y cable. So when I activate the rudder the gun turns. In my model I only powered the two outboard engines. Care must be given to drill out the two shaft housings and to open the hull. For the prop shaft housings I used K&S brass tubing, but a lubricating system is needed to prevent overheating of the shafts. I am sorry I cannot send you with this reply the drawings of my concept of a prop shaft bearing with lubricating tubes. If you reply to my email address (wdevallette@prodigi.net) I'll send it you as an attachment. Locate the RC receiver as far away from the motors as possible same with the RC antenna. The heavy battery is located midships, just a bit aft, motors just forward of the battery and the speed control ditto.
The Lürssen effect can be achieved via the rudder pushrods. I did not buy the crew members from Italieri, but I cannibalized an old model of a KFK armed trawler with Tamiya guns and repainted those gunners.
LED's in red & green can be had from Radioshack and be installed on the bridge replacing the plastic running lights. An RDF antenna I made from fine brass wire. I also replaced some of the fine plastic wiring on deck with brass. The railings are covered with "canvas" dodgers (covers) made from one inch wide cotton tape out of my wife sewing box.
I used a two channel Futaba RC unit and was able to buy for just a few dollars a couple of extra servos and extension cables on Ebay. Originally I used a Pro-Boat speed control (with reverse) but it was designed for only one motor and put out a lot of chatter. So I replaced the unit with an older Futaba speed control that can handle multiple e-motors. For a battery I am using a small 6volt 1.3AH Intestate battery, about 3.5 x 2 x 1. They hold a charge much longer than those multi cell jobs designed for RC.
One final advise, those Schnellboote were not painted red under the waterline, The dockyard painted the underwater part of the hull with a black anti fouling paint, some boats had a narrow Red waterline, for which I used red racing stripes. I also added some spots of "rust" on the hull to make the model look somewhat worn.
Of course there is no evidence but I thought about building a Flatner Girocopter and have it replace the mine racks. You know those Flatners were towed by a U-boot to increase their circle of vision. With the high speed of the model it might even fly???? Oh, I forgot I am using Speed 400 6 volt motors with 0.1 microFarad suppressors over the terminals.
Well as a "by the way" item: my uncle served on one of those boats with the 4th, Schnellboot Flotilla in the channel and later in the Med. he had some interesting anecdotes to tell like when his boat boarded a Royal Navy navy torpedo boat in the channell. Not knowing what to do with their prisoners the Germans dumped all their weaponry, ammo, small arms, torps, took all their tea and chocolate and send them home, since the Britisher's life rafts were shot up. My uncle also took part of Operation Cerberus, the break out of the German fleet from Brest. His boat stayed with the mined battleship Scharnhorst until it could proceed.
Good luck with your project. It's up to you if you want to use the flag supplied with the kit, but to be correct the swastika should be part of the flag, after all that's the flag the crews served under and also died under.
Kind regards Koelschwolf In Dallas, Texas