So to solve the issue of Existing AMPRnet tunnel users not being able to reach BGP announced 44-net IP Space I've drawing the below drawing that shows how this can be done without having Brian Kantor ask UCSD to make any network/routing changes. This only requires at least 1 (or more) ISP (or companies running BGP) willing to setup a BGP over GRE tunnel to Brian's server to make this work. There are currently two ISP I know of willing to do this if Brian is willing to do this on the AMPRnet Server shown in the drawing. This only requires setting up BGP with a route-map for changing the next hop IP's and running GRE tunnels on his server. The bonus is he can set this up with multiple ISP so that there is redundancy. Since the ISP is only sending BGP routes of the 44 IP Space of size /16-/24, this will not consume very much routing table space on his box (currently 53 prefixes). I also have to imagine the bandwidth going over this GRE tunnels not going to be a huge amount.
So to summarize how this work. AMPRnet tunnel users can send traffic to a BGP announced 44 ip space which would travel over their IPIP tunnels (perhaps a low pref 44.0.0.0/8 route to UCSD in rip? or inject the BGP routes into RIP) back to UCSD and then over the GRE tunnel to a ISP and then ride the internet to get to that BGP announced block. Return traffic would just follow the existing internet routing table and come back via the UCSD network.
AMPRNet Interoperability with BGP Drawing: https://www.osburn.com/amprnet-150614-1.0.0-bgptunnels.jpg
Tim Osburn www.osburn.com W7RSZ