I have these, and way back in the '80s, our local Star Trek club wanted to make our own uniforms. We wanted to be post-TOS, pre-TNG (TNG was the only spinoff series at the time)... so I dug out the Tech Manual, turned to the pages on uniforms, and started sketching. We came up with a design that was basically a mix of TOS and TOS-movie tunics, TNG pants (as in separate from the tops), but with a vertical stripe denoting Command, Sciences, or Support on the outside of each leg. We left the black boots up to each member to acquire their own.
And we drove the clerk at the fabric store nuts; she kept trying to sell us this striking red material, and we kept telling her no - because if we wore red, we'd end up getting killed!
This was pre-combadge, and I remember one night at the convention when we were expecting to debut our uniforms... the member working on my tunic called my room in a panic, saying she'd accidentally sewn my insignia on sideways