This very nice HO gauge locomotive by Roco is 43507 a SBB Be 4/6 electric locomotive in green livery, it has running number 12323. 

The Be 4/6 was a bogie locomotive operated by the Schweizerischen Bundesbahnen (Swiss Federal Railways) (SBB) on the Gotthard Railway along with the Be 3/5, The design was based on the prototype Be 4/6 12302.

The design of the locomotive was derived from Be 4/6 12302, particularly the first batch, numbers 12303 to 12312. Traction was provided by two electric motors, one mounted in each bogie. The motors drove two drive axles. Each bogie also had an unpowered running axle. 

Between 1 February and 30 June 1920, the first series (12303-12312) were put into operation from the Bern depot. They had first proved themselves between Lötschbergbahn and Brig-Glis. 12303-12307 were transferred to Erstfeld in early summer 1920 to test for trial the first electrified section of Erstfeld-Göschenen, returning to Bern between August 1921 and January 1922. In 1924, the entire first series without electric brake (12303-12312) was assigned to the Zurich depot. With the exception of the 12303, which spent 1929-1947 and 1950–1955 in Bern, they remained based in Zurich until 1962, when they were allotted to the Winterthur depot until they were phased out.

Locomotives 12313-12316 were delivered to Bern from 12 January 1921 to 19 July 1921, and were then transferred to Erstfeld. Locomotives 12317-12342 were delivered directly to the Gotthard between April 1921 and April 1923 and distributed to Erstfeld and Bellinzona. The depot in Lucerne received 12313–12340 in 1924, some moving to Olten in November 1927. The Zurich depot was given 12313 and 12314 in 1928 and 1929 and further movements happened as needs changed.

The Be 4/6 pulled all major express trains on the lines they served, including those between Schaffhausen and Zurich, until 1929 when the Ae 4/7 started replacing them. By 1938, the type had been largely replaced by Ae 4/7 and Ae 8/14 in express service in Gotthard, finally disappearing in 1962 with the increasing introduction of the Ae 6/6.

Freight was also pulled, particularly from the depot at Olten, which served Basel and Zurich for decades. By 1955, the movement of locomotives to Biel/Bienne was part of a general trend moving the locomotives to the lowlands. However, they required an ever-increasing amount of repair and maintenance, and retirement started in April 1965 with 12312, with locomotive number 12339 the last discarded in February 1976.

Three remain in preservation including 12320 which is in operational condition, meaning that this loco would suit both a period or modern layout. 

The loco is in very good condition as you can see in the pictures, it is tested and runs with working lights, a complete external visual inspection has shown the overall condition is very good. It comes complete with its box. 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!).