I’d use the original headset cable stop that is still installed on the bike. I’d investigate the angle of the straddle cable. I’m going to sag it at 135 degrees. I start at 90 degrees.
Almost all of your stopping power is up front. So I’d focus there.
The way the front is set up, you have minimal cable travel from the straddle cable hanger to the cable stop.
Since you like the fit of the bike, I’d stick with the frame.
Not sure where you are located, here in the US I’d head to the closest co op and find better brake calipers for the front. Clean everything, grease the canti posts, reassemble and you are set. If stopping is your primary goal while staying at a relatively low cost, just do the front. Google bike stopping power, front versus rear brake.
Last edited by wrk101; 11-23-22 at 11:09 PM.