Luftwaffe Chronograph

[rolandtg]

Recently I was going through some things I got when my Grandfather passed away and I found this watch.
Grandpa was an avid metal detector enthusiast and I suspect he dug this up one day somewhere.

As far as I can tell it's a Tutima Glashutte Luftwaffe Chronograph circa 1941. Inside the back its signed with
Wassergeschutz, Boden Edelstahl, *
Uhrenfabrik AG Glashutte
Which I guess means waterproof/shock resistant watch factory AG Glashutte.

Sadly, it appears the mainspring is broken but the internals look good otherwise. I spoke with a local watch shop and they estimated it would cost around $1K to repair if they could get parts. The local shop didn't know much about it but they did make me a surprisingly reasonable offer for the condition based on blue book value.
Looking around the internet I can see that these watches are apparently quite valuable (although prices vary wildly) but there is little information beyond that.

Anybody out there a watch collector who might have some more information about these watches?
Here's another example:
http://www.farfo.com/menswatches/Pag...ronograph.html