So I decided to try our TomoatoUSB on my old WRT54GS v2, which already had Tomato 1.28 on it, running like a champ.
I downloaded the NoUSB-VPN MIPSR2 (tomato-K26-1.28.9054MIPSR2-beta-vpn3.6.trx) file and flashed it to my router using the built in Upgrade web interface
The flash was "successful" and the router rebooted and greeted me with a blinking power light. I attempted a 30/30/30 reset to no avail. Router is not pingable what-so-ever and does not seem recoverable.
What did I mess up here? Seemed pretty straight-forward.