On the Army Pistol, which the 1901 Target is made on, the one screw that you access from the lower portion of the front grip strap is the only screw that holds the grip onto the frame.
That screw, if original and not some sort of aftermarket attachment,, is long enough to extend all the way to the inside of the lower portion of the back strap.
There, it screws into a reinforced section of the backstrap and does not show on the outside of the backstrap itself.
The screw travels through a tightly bored hole in the grip to keep the grip securely in place on the frame..
Just above that point on the outside of the backstrap you can see the end of another screw. That one is a screw that is holding the mainspring onto the inside of the backstrap. You can get at that if needed once the grip is off.
If you have removed the screw from the front strap and it appears to be the correct one.,,
The grip should pull straight down and off of the frame tangs.
There is always the possibility that the grip was loose or someone 'tightened the fit' at some point with something like cardboard shims, glue, who knows what people may try and do.
But just that one screw removal is the Factory disassembly.
Here's a parts schematic for the Target pistol you may find handy as well.
Part #30,,Tang Screw (First part on the Left,,Second Row from the Top)
This is the 'Grip Screw' that comes in from the front grip strap and threads internally into the reinforcement on the inside of the frontstrap.
Added:
Just for the heck of it I looked up the Uberti Rolling Block Target pistol.
They made the grip attachment on that pistol the same as the orig Remington w/ the one screw. But they didn't make it a blind hole in the backstrap as Remington did.
Uberti Rolling Block Pistol - VTIGunparts.com Online Store
