The main differences between the T and TV models were:
Frame: T - pressed steel / TV - twin tubular steel downtubes (in
1958 the T-model also received a similar frame)
Suspension: TV upgraded from T model
Brakes: TV - full-width from brake
Headlight: TV light incorporated in a nacelle above the front fork.
By 1959 the TV disappeared and only the T remained and was also
discontinued the following year - the era of pushrod engines were
something of the past and OHC models were in full swing.