I have a standalone fiberglass shower in my master bath that appears to be original to the house (built in 1970). There is a leak in the drain--as evidenced by a circular water ring on the first floor ceiling beneath the drain. I looked up several videos online, however those all deal with newer plumbing. My drain appears to all be connected in one metal (copper?) piece. Is that possible? just wanting some thoughts on how to fix the leak without tearing a hole in the ceiling. I'll try to post a couple pics with this.

that's a hard one to tell for sure since there is no pipe in the drain.
I would say that you need a plumber who can pack and pour a lead joint which is what that drain was designed for.
then you can run some proper tests to be sure that was the problem in the first place.

I am just shooting from the hip as I cannot see the photo. I would open up the ceiling to verify where it is leaking from. Drywall is not hard to fix, but plumbers aint cheap.

right click on the red X. go to properties. copy the address and paste it in the address bar.

It looks to me like they leaded a bushing in the drain and sweated the copper to the bushing.

i really can't tell for sure what i'm seeing.

I second opening up the ceiling. Make sure the leak is from the drain, which it very well may be the case. But make sure the valve in the wall is not leaking when you turn the water on.

yes... before opening the ceiling... remove the trim around the shower valve and open the valve to let the water run and look in there with a flashlight to see if its dripping in there behind the wall