The first style of loading gate was called a flatgate, just aflat piece w/ a little fingernail slot.
I guess it probably saved a few pennies.
A Premier loading gate was a aftermarket round loading gate made as an accessory to change out the flat loading gate. After a while Ruger did away w/ the flatgate and went with the roundgate as standard. Sort of...
Because the premier loading gate "wraped around a little farther and I think looks a little better.
Standard Loading Gate, Front to Rear .475
Premier Loading Gate, Front to Rear .575 ~ .590
Premier Loading Gates even showed up on a few Rugers finest engraved guns.
Your sn# tells us you probably have a standard loading gate. IMO you still have one of the nicest shooting .22 handguns ever made, now go try and wear it out. :roll: