FT Castle had a garage situated on the Charlton Green side of St C/Katherine's Place (as shown in the 1927 pikes directory).
NB FT Castle was also involved in the Niblett Garage at 8 Park Place.
I have no images of this garage, but from this old 1871 map you may be able to work out where roughly where it was.
1914 Pikes - nothing listed at this site
pikes 1923 - Castle F T, Bridge Street
27 April 1923 (DE) - Advert
2 May 1924 (DE) - Advert
1927 Pikes - Castle, F. T. motor engineer. (also see 8 Park Place)
1931-2 Pikes - Castle, F. T.
1935-6 Pikes - W Newing, builder's yard.
NB there was an advert in 1930 that showed W Newing at 21 Granville Street, so he had been trading before he moved to the old garage site.
1938-9 Pikes - nothing listed here
I think that this builders yard, may turn in to Tapley's garage, but as yet do not have evidence... see here