The 20TA trials model was introduced for the 1958 season having been awarded the name "Scottish" to commemorate Jack Simpson's first win for the Greeves team in the 200cc class of the 1957 Scottish Six Days Trial. The new model, which benefited greatly from Brian Stonebridge's development efforts, employed the 20SA scrambles frame equipped with revised footrests and a sprung saddle and housed a Villiers 9E engine fitted with a wide ratio gearbox, a longer inlet manifold for the Villiers S25 carburettor providing more torque at lower rpms coupled with a raised exhaust and modified Villiers muffler.

The TE and TES machines used 250cc 32A Villiers engine, the TES utilising a Greeves factory alloy barrel and cylinder head.

The Scottish monicker remained in place until 1967 when the Anglian and Wessex models were introduced.