Appropriate Greaves?

[M. Caecilius]

Yes, I have a set of each of those, for a second century impression, and later.
If yo ugo back to republican times, then there was more comon use of greaves, but possibly only on one leg for a miles.

What would the particularities of Republican leading-leg-only greaves be? Both with a view to buying (= good replica) and for general knowledge (=recognising them when seeing them).