how rare were / are these grip frames???

[LeverGunner]

I had no idea that such was ever made. I am certainly interested in the history of them, as well as some better pics. Thanks for sharing MWM

[grandpa]

I also have a consecutive pair of Montados with the grooved front straps. They were grooved for the first year's production, then changed to smooth. Probably because of SASS. I have fired mine with cowboy loads and can't tell any real difference in the way they feel or handle. Never had any reason to load them with anything that might have heavier recoil but the grooves are not so sharp that they would be uncomfortable.
The grip panels on any handgun will be more important for control than the front strap because the panels are a much larger surface area.