In research I discovered that Richard Hatch did not have a regular lefty holster made for him (they seemed to have only produced right-handed holsters in pre-production) - I can only assume that at the last second wardrobe found out that one of their
stars was left-handed & cranked one out
just before filming.
As to how they did it... look closely.
LOL, all they did was slide a righty holster to the left side & chop a path through what WAS the front to allow for the trigger guard to slide through (A).
Notice (B) that the space was closed up some to hold the laser tight.
So, Apollo had a rather unique holster. Here's my version:
And with gun securely in it:
Update when I'm actually done.