The first important development stage of the basic TL model was the introduction of the TLT type version. Here the second T refers to the fully enclosed rear chain drive, which was considered important when considering the quality of the chain at this time. Additional comfort was provided with the use of a dual seat, while general appearance was improved with the use an improved form toolbox, one of which contained the 6-volt accumulator. To avoid the use of imported components, a home produced Amal type carburettor was adopted, and an AVF product replaced the previous Hella headlamp unit.