hey Alex,
welcome to the Board!
although i haven't heard of anyone running these mics for concert recording, i'm sure someone is or has.
judging by the available info, these mics look to be just fine for this purpose. specs look decent. looks as if the LD v67g has a fairly flat response curve. the SD 603s a definate rise from 5k-> 20k peaking at 10k. that being said, i'm suspecting there will be a noticable difference in sound between the 2 mics you have listed.
the Wide Card pattern is one that is not among the most popular among concert Tapers. not sure if that has to do with the pattern itself, or the fact that some of the popular microphone manufacturers don't offer this pattern. i know DPA offers Wide Card. i'm sure some folks on this list can offer opinions having run that pattern in different situations.
if you have both sets at your disposal, i'd say definately give them both a shot and see if you like their performance. get yourself some recordings of other microphone brands/ setups and see what type sound it is exactly that you like. then see how these compare. there are plenty of people on this Board with many different mics/ recording setups. i'm sure you'll have no trouble finding folks to help with opinions/ other recordings.
good luck, and let us know how these work out for you in the field.
peace
~Scott