NavList:

Back on Feb. 1, 2012, NavList member Philip Lange forwarded a "Liveaboard" List message from someone named Wayne offering the HP41 Navigation Module.  A few of us, including me, responded.  I was not quick enough, because on Feb. 2 Philip told NavList that it was already claimed and told me that it was already spoken for, but never said who got it.  You can find some of this in the NavList archives, including Philip's email address (which might no longer be valid), if you want to try to track down the module and maybe "make an offer".

The code for each of the parts of the module is downloadable for free on the HP Museum site (http://www.hpmuseum.org/software/swcdp.htm). (Actually it is the HP-67 Navigation Pac ported to the HP-41C.) 

I downloaded all of it years ago but never had the energy to punch it in.  (Then the hard drive it was on died.)  It is also available on CD (CD-07) for $10 (http://www.hpmuseum.org/cgi-bin/orderform.cgi?paypal07), along with instructions on how to get it into your calculator, which, as I recall, is not that straightforward.

Stan