Thank you so very much for the through response it helps a lot And is greatly appreciated!!! That now being said it has been well cared for, kept clean/maintained, but not fired in some time, as my uncle is older and unable to now.... Out of curiosity, what would shoot a .32-20 WCF? He had another "police positive" 4 in, with less info. (My dad has a spreadsheet of his collection and I'm wondering if something got transfers from voice to paper? Do they even make .32-20 WCF any more....? (That's what it was listed on the spreadsheet as, hence the ammo question)Welcome to the Colt Forum! Thanks for sharing your wonderful soon to be heirloom with us. You're in the right spot to learn more about it.
For a general overview of your revolver, check out this link: Pocket Positive
Simplest put, the Pocket Positive is the smallest 'modern' swingout revolver Colt made, featuring their 'positive' technology making it much safer from accidental discharge. The insides of that little guy are on par with and was the basis for every revolver Colt made throughout the 20th century. Every revolver after utilized its design. With the serial you provided, that would place your gun sometime around 1927, so it is likely a late 'first issue' Pocket Positive. Around 1928 is when Colt made a couple of changes and became what collectors refer to as the 'second issue.'
From my understanding, I do not believe those are the correct grips. They would have been added later as a personalization. Factory grips on a Pocket Positive almost always were either black hard rubber stocks or standard checkered walnut stocks. Colt began transitioning to walnut around 1924, but it's possible yours originally left with either when it was shipped.
With my mention that it's the smallest 'modern' swingout revolver and comparable to any of Colt's other revolvers from the 1900's, it's perfectly safe to carry, shoot, and enjoy. You may want to have a qualified gunsmith look it over before shooting it unless you know your uncle had maintained its condition.
And now finally, as you noted your gun is .32 Colt New Police. That's effectively identical to .32 S&W Long, and any .32 S&W Long ammo will work. Back in the day, Colt didn't want to put their competitors name on their guns, so they created an identical cartridge with a flat nose and gave it a new name. For sake of purpose, there is no difference. Definitely don't try shooting .32-20 WCF in it, but feel more than free to take it to the range (or backyard if you're out far enough in the country) and can find some ammo for it. They're great little guns.
If you have any other questions feel free to ask. I am sure other people will be by to fill in the blanks I may have forgot, but hopefully this helped! I've never owned a Colt Pocket Positive, but I'd like to and intend to get one sometime. Let us know how it goes when you get it and what you decide to do.
All this info again is very helpful and appreciated!