I've only worked on a few older 10/12 speeds and ran across this yesterday. These are stem mounted shifters that seem to be spring loaded, and also have a spring return lock pin. What is the purpose of this setup? Are having these shifters any indication of the age or quality level of the bike? Thanks!

And they say "finger tip" on the levers.

I recall working on bikes with those. Those pins let you "lock" the shifters in the forward position, presumably for adjusting the derailleurs at zero cable slack, but once adjusted and with the pins retracted you could actually move the shifters forward even a little more. Maybe the buttons were meant to function as an anti-theft device.

In general for any early bike to have the shifter on the stem was a sign of low price.

Another easy way to spot a cheap bike, look at the dropouts. Stamped metal dropouts == cheap bike. Chromed contact surface dropouts on early bikes meant top frame. Lots of good and bad frames in-between.