Since the Reichsbahn in the GDR realized that the use of steam locomotives would still be necessary for a long time, many locomotives were rebuilt from scratch. The class 01 express locomotives in particular were to remain indispensable for a long time to come. From 1962, a total of 35 of the newer 01s with larger leading wheels and reinforced brakes were brought to RAW Meiningen. The conversions were completed in 1965 and the affected locomotives became 01 501 to 01 535.
The heart of the rebuild was the new boiler, which was all-welded and featured a combustion chamber. What was striking on the top of the boiler was the one-piece cladding of the domes in the form of a ridge. The cylinders were also new welded constructions on most locomotives, as was the cab. Other new parts included a new feedwater heater, Trofimoff valves and an Indusi. The locomotives with broken spokes on the driving wheels were given new Boxpok wheels known from American locomotives. These had no spokes, were hollow inside and had large holes. Since the Boxpok wheels available in the GDR were not of high manufacturing quality, they often had to be replaced later with spoke wheels.
The second half of the rebuilt locomotives were oil-fired ex works, with all but seven of the others being retrofitted. From 1970 onwards, all oil-fired locomotives were classified as class 0105 and the remaining coal-fired ones as class 0115. During the oil crisis at the beginning of the 1980s, the 0105 were stored and there was no conversion to coal firing. After their withdrawal, some locomotives were still used as heating locomotives. Six were preserved, one of which was left in service as a traditional locomotive from 1984 and two of which were later refurbished to be operational again.
