I got some bits for the 20. I ordered them through work.
I got a brake roller thing. I thought it was to enable me to use old style levers with V brakes.
Ive got a sidepull brake on the back just now..a Weimmann 1080.
Same as I have on the back of my Gold bike a Raleigh Phaser kids bike from the 70s....that Ive converted to a MTB.

The back brake on that and now the one on my 20 feels horrible. V brake levers pull a lot more cable.
So the lever doesnt move much....just feels solid....and theres not much ***********....admittedly Ive got old pads on...but its hopeless....also tough on my hand.
I put a bracket to hold the cable...so I can use a cantilever brake on my suspension forks, on Gold bike

Got another bracket, so might do the same to my 20. Seen them in the catalogue too, there £8

Heres a pic of the 20. With that roller thing on the V brake. But Ive took it off and put a 135degree noodle, and V brake levers.

Ive changed the gear shifter too. The trigger couldnt select first gear. As the lever would hit the straight bars. Fitted a twist grip. Some shoppers came with them. Couldnt find a cable as long. it works, but I would like a bit more length... :-)
Heres what I did to make the trigger work.

Strapped the cable to the bars. Then grab the shifter to change