Thanks for the comments RF'rs!
It's really easy using this combo as you zone focus most of the time, and the Color Skopar is the snapshot version which has preset detents at various focussing distances. I also measured my steps - two steps = 3 feet - which makes it even easier to estimate distances.
But for outdoors in daylight, it would be very difficult to miss focus with the 25mm lens!
The only issues I have had with the 1f is fiddly film loading, but it seems I've figured that out (thanks to threads on this site). Everything else has been a joy. I also use an MdA (Leica M4 w/o rangefinder) but the advantage of the 1f (and 1c) is it is smaller, but more importantly the external VF is in perfect line with the lens axis. On the MdA it is off set.
I tested the camera at all speeds to make sure the curtain timing etc is ok. No issues. The CLA by Youxin is perfect (as well as quick and cheap!)
All these things are just light tight boxes with a lens and shutter. The shots would have looked exactly the same if I used my Nikon F6 w/ 24mm AIS lens! Kinda sobering...