that would know definitively and I've personally lost track of him. Steve Holmgren and the Arpanet Unix team are still around (at least they were 3 years ago). I just remembered that I put some of my notes & findings in a draft wiki that I wanted to develop for TUHS - but I never finished it: http://chiselapp.com/user/pnr/repository/TUHS_wiki/wiki?name=early_networki… The recent find of CSRG report 3 and 4 may be the incentive I needed to complete my notes about 4.1a, 4.1c and 4.2BSD. However, still looking for the actual source tape to 4.1a - the closest I have is its derivative in 2.9BSD (https://minnie.tuhs.org/cgi-bin/utree.pl?file=2.9BSD/usr/net)