2 matching mags "supposedly" add 50% value, one matching mag is maybe 20%, and LOTS of faked matched mag to guns out there.
Rare is a hard term.. on ebay, lots of things are rare, and aren't. How many 1914's were made, as compared to a 1910? That is rarer, it is rarer to find a 1910 with matching magazine than a 1914...
BTW, what the hell is the stamping on the frame rail?
Ed