So that was all stupidly easy
I used the adapters off the old cable tektro calipers. All fitted very easily, no rubbing, didn't need to adjust anything.
Went out for a test ride - it's miles better, I can lock the rear wheel up now. Much less effort and better modulation. Possibly not as good as MT200s in mountain bikes but not far off. Hopefully should improve further as the pads bed in.
I asked the bike shop how much it was to get TRP HY/RD cable activated hydraulic pistons : £130 each front and back + £40 bleeding ? / fitting + compressionless cable
(I saw a tip to cable tie the brake cable every few cm as a alternative to compressionless housing so I did that)
So my alternatives were full hydraulic group set (£799 !), bike shop TRP HY/RDs (>£300 ) or these BR-005s(£26 + £5 tax) and fit them myself. (This was for a bike that cost £250 off marketplace)
Looking good so far, will post any relevant updates