Have just come across this thread. 
I have one of the original issue of the BachFar 64XXs (6412 in BR lined green). I will always say that the Dapol 57XX/8750 pannier is an excellent model, but it seems to be a disappointing runner - mine has expired - and it's noisy (too darned noisy!). My 64XX is quite capable of handling six BachFar Hawksworth coaches, though on my layout it will be confined to what it was designed to do - hauling Auto-trailers, or working with a B-Set.  It is a superbly quiet runner.
To be rather pedantic, the 64XX Class were only 40 in number, being built in four Lots between 1932 and 1937; they were designed principally for work in South Wales where the 48/14XX 0-4-2T locomotives were at a disadvantage on the steep gradients of the lines in the Valleys. To be even more pedantic, my copy of the RCTS "Locomotives of the Great Western Railway" part 6 informs us that 25 of these locomotives were initially sent to work in the Cardiff and Newport Valleys, and between Pontypool Road and Swansea, and also between Swansea and Carmarthen. 8 were sent to Plymouth (Laira) for working the Saltash suburban services (frequently sandwiched between two pairs of auto-trailers); 2 more went to Kidderminster Shed; 3 more were at Stourbridge; and 2 more went to Wolverhampton (Stafford Road Shed).
By 1954, South Wales had gained 5 more, from other Divisions, to work the former LMS lines between Abergavenny and Merthyr, and between Nantybwch and Risca.
BR classified the 64XX Class 0-6-0PTs as 2P.