This very nice and rare 3-rail AC HO gauge locomotive by Marklin is 3602 a model of the planned but never built Reichsbahn BR 53 2-6-8-0 steam locomotive in grey livery. It has running number 53 0001. 

This is an extremely unusual model as it is of a locomotive that never really existed. In 1943, designs were sought for “War Locomotives”, to be built to a few standard designs for use on the Reichsbahn. The Class 53 locomotives were to be one of 3 war austerity classes of locomotives, built following plans submitted by the Borsig locomotive works in Berlin. The Class 53 locomotives were designed to be able to haul a 1,700 ton freight train as speeds up to 80 km/hour [50 mph]. Work began on the first Class 53 in 1944, but the Borsig plant was badly damaged in bombing raids on Berlin, and the frame, wheels and boiler of the new locomotive were shipped to Henschel, in Kassel. By mid-1944, the war was going badly for Germany , and Berlin was under severe air attacks, and it was decided that tanks were needed more than locomotives. Resources and supplies were diverted, and the Class 53 locomotive was never completed. The running number 0001 on the model is just a logical number, given by Marklin. 

The loco is in good condition as you can see in the pictures, We are unable to test it as we do not have a three rail AC test rig or track, so we have not tested it but can see no reason why it would not run. It is sold in untested condition, this means that it may not run, and as such it is not being sold in running condition. However a complete external visual inspection has shown no reason why this loco would not run and the overall condition is very good. The box is in good if slightly shelf worn condition. 

Overall this is a really nice scale locomotive and would look fantastic on a layout.

Do please have a look at my other listings, I typically have various HO and OO locos on offer as well as an extensive range of imported N gauge locos and other items. 

Note: I do recommend all locos are cleaned & serviced, as they have some age to them even if the quality looks at the highest level (fairly standard advice for all locos!).