Sounds like its in what I call shooter condition. Scratched and pitted - original finish sounds like it's beyond gone. Not much collector's value (pictures would help). I'd say it's worth somewhere between $900 - $1,200. If parts have been replaced, then possibly less. I don't see that many really early ones, from 1913 - so I'm not saying there's no collector's value - there could be some, thus why my range goes to $1,200.
FWIW, I've been following the auctions on 1911's made from 1913 - 1919. Lots of folks like the military guns. I prefer the commercial version - better finish and finishing on the commercial guns....I'm just a sucker for pretty guns.
There are some really nice commercial 1911's from that era that come up from time to time - strike price on those in excellent condition is $2,500 +/-.