$200 + in that condition easy. I'll try and pull out "The Duck Calls of Minnesota" this weekend and be able to tell you the model number. 1930's-1940's.
Here's a goose call from the same period of time:

Note the funky "Herter's" V bend in the old metal reed. Note also that the insert is machined to screw in to the barrel....took me forever to figure out how to take it apart.
Assembled:

There was one on ebay recently where the guy put one of those duck calls into a MUCH more recent goose call box and it sold for over $300. The collectors would not have been fooled. The pristine condition is extraordinary. I'll see if I can find the listing.
Found it.....see if this doesn't look like what you got:
http://www.ebay.com/itm/WW2-VINTAGE-HERTERS-377-NUMARA-TYPE-GOOSE-CALL-W-ORIGINAL-BOX-amp-PAPERWORK-NICE-/361054221344?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2047675.l2557&nma=true&si=Xq%252F0CBZoT%252Fgq3eDMfH6k9mQm1uA%253D&orig_cvip=true&rt=nc
http://www.auctiva.com/hostedimages/showimage.aspx?gid=488414&ppid=1122&image=785924999&images=785924980,785924985,785924991,785924999,785925003,785925009,785925016&formats=0,0,0,0,0,0,0&format=0