NMJ Topline model of SJ B1c 5166 Restaurant-, 2 Cl. coach, original version 1968
25 combined Restaurant and passenger coaches with the numbers 5166-5190 was delivered from Kalmar Verkstad (bodies) and SJ Verkstad Örebro for the interior and equipment 1968-1969.
Seating capacity was 16 in the 2 Cl. saloon and the restaurant had seating places for 32.
The RB1`s were put into service on the long-distance trains from Stockholm to Gothenburg, Malmö, Östersund and on the lines up to Norrland.