Turns out I had the wrong version of Backfire 10.03.1 in the router.  That the kernel version was something other than 2.6.32.27 and thus opkg didn't have some of the packages I needed for the USB mod.  I then SSH'ed into the router so I could do

cd /tmp/
wget http://downloads.openwrt.org/backfire/1 … uashfs.trx
mtd write /tmp/openwrt-brcm47xx-squashfs.trx linux && reboot

And then I had the correct version. 

Went back into the web GUI of Backfire, and did an "update lists".  Once I had the items installed, a couple of iterations of fooling around with the "mount points" I was able to see the files on the USB sticks I plugged into the router.  I had a couple more WRT54Gv2's which I did the mods on, and got them to work. 
(hey, I'm a hardware guy, not software)...

See http://www.wa2ise.com/radios/WRT54Gv2USBmod.html for more details.

For grins, I used a USB hub connect to the router's new USB jack to see if I could have two USB sticks connected.  At least the particular hub I used, it worked.  The first USB stick was "sda1" and the 2nd was "sdb1".

(Last edited by wa2ise on 16 Nov 2017, 05:37)