Quite correct - the LOAD 1 TON or LOAD 2 TONS was carried over from the SR but in block capitals rather than the original SR script
Load 1 Ton or
Load 2 Tons.
I'll try and assist with the rest....
I have looked at a few of the colour photographs in my SR books and the lettering colour on pre- 1960 photos appears (whilst bearing in mind the reproduction quality) to be a cream/straw yellow colour but a photo of a recently overhauled Maunsell brake coach in 1961 shows the lettering to be yellow (1st class stripe yellow?).
It could well be the lettering colour changed to yellow possibly with the introduction of the new 4 CEP/4 BEP electric stock in 1957/9 which had yellow lettering.
The lettering colour will largely depend on when and where the carriages were last overhauled and ideally you would require the overhaul dates for set 245 - which I have not found in my books. I assume 245 is still the set number? I say 'where' as Lancing, Ashford and Eastleigh were not unknown to do their own thing when using up surplus transfers.
The above does not really answer your query, however, as set 245 was effectively broken up by the end of 1962 (below) I would stick my neck on the line say the lettering would have been cream/straw yellow rather than a full yellow - unless the set was overhauled during 1957/60. 1959-63 saw the withdrawal of large numbers of Maunsell carriage stock mainly due to electrification.
Brake third 3785 - set 245 from inception until withdrawn 11/62.
Composite 5658 - set 245 from 1951 until withdrawn 1/62.
Brake third 3789 - set 245 from 1948 until withdrawn 11/62.