The Old Republic lacking captital ships ?
I think that doesn't work with the "history" - there were wars before "the galactic civil war" - and some had bigger fleets than the Empire, but that is EU ...
The Rebels/Alliance had no such rich, massive resources as the Empire has - they got all the major players, that build equipment for the Republic too
and our "fighters for freedom" use all means, speaking of old used gear, what they can find and get hands on - only later in the conflict groups with money and connections, join the "good cause" and better weapons are build.
So keep the good stuf, but try to give them visual unique style, so we can for one say it is Repulic and secondly a "protoype" for later Imperial vehicles - "Dreadnaughts" anyone ?