claus wrote:
... Is there a way to have some of these charts scanned and converted to
electronic raster charts? ...

You could try scanning them yourself and using something like
http://www.oziexplorer.com/. I tried this method some years ago when
Ozi first came out and had some problems. At that time the program
didn't work correctly for charts that crossed the 180 meridian and I
found that I got noticable edge to edge distortion on both the
individual scans and the stiched product. Your flat bed scanner might
be better than mine was and I'm sure that the program has been updated
since I last looked at it... However, if you use scanned charts to
naivgate with you should be aware that they my have distortions. If
you are still a Loran user you will want to be particularly careful of
scanned or copied charts. Given the possiblity for errors and the cost
of Ozi I can't honestly say this option makes much sense for places
that have digital charts commercially available, but it may be fun to
try and the demo ware is free.

--Tom.