I do indeed have the wrong brake/shifters on flat bars, they are Shimano ST-EF35-8 and ST-ET35L,
I’m not surprised that braking performance was poor with V brake specific levers. I would make it a priority to fit full size V brake callipers both front and rear before I rode that bike much further.
Decent V brakes aren’t expensive and there’s a good supply on the secondhand market. The cheapest options generally use the frame mounting boss as a pivot bearing. Paying a little more will get you internal pivot bearing bushes and better brake shoes with replaceable pad option.
Thank you - that was what I was trying to do, but on checking the brake bosses on the forks, they are @67mm centre to centre, from my reading around I think any V-brake needs something closer to 80mm apart, I assume they would fit after a fashion, but the arms not be parallel to the forks?
I'm going to have to rethink everything, it might just be easier to remove the combined brake/shifters and fit separate brake levers and shifters, again nothing I know about apart other than it's a triple front chain ring and 8 gears at the back.
Again, thank you all for the advice, it does seem to be a mine field and I seem to have bought a 'pig in a poke'