Not all 19th century French bows are created equal, so the first item on a check list when considering a bow is the quality of the wood used (for me always pernambucco), and the skill of the maker, this will determine all other factors. Correcting a poor/crooked camber on a lesser quality stick will not make it a great "player" for modern use irrespective of the maker. The ideal is a combination of strength and flexibility.
Personally, I have never taken the "balance point" into consideration. Apart from the weight of lapping used, older 'cello bows can vary considerably in length, gauge of metal mounts and frog size, but a fine bow will always tell you "what to do" to obtain the best results. The optimum weight is up to the individual player, my preference pivots around the 80 gram mark ('cello bow), but I know fellow professionals who prefer both much heavier or somewhat lighter bows. In my opinion fine early 19th century bows need not be "cranked up" pretty tight, that way they are liable lose the very qualities of suppleness and tonal variety for which they are renowned.