The parts fitted to the TR4 and TR4A are largely the same but the TR4 part is slightly longer where it enters the switch plinth. Only one part is currently available to cover both models and there is only one manufacturer we know of.
This problem has been identified on a RHD car and may well apply to a LHD cars too.
TR4 lower dash pads had a heavy grain whereas TR4A to TR6 had a lighter grain.
As TR4 pads are not available, the TR4A part can be used for the passenger side with the grab handle and the TR6 part which is plain can be used for the driver s side.