Fix up logic mistakes in the following text:
Four experimental 4-wheel cars were built in 1939-40 (nos. 1001 to 1004). More would likely have followed had it not been for the Second World War, which prevented large scale fleet renewal.
Four experimental 4-wheel cars were built in 1939-40 (nos. 1001 to 1004) and more would likely have followed had it not been for the Second World War, which prevented large scale fleet renewal.