Building an updated version of Shibby's Tomato for the WNR-3500Lv2

I really like Shibby's Tomato, but the last release was in April 2014.  I found a post on building DD-WRT, but it dates from 2010-2012 and is out of date.  A number of its links, and links to links are dead.  The last release notes on DD-WRT noted a number of bugs fixed in WDS (several by Kong) and more may have been fixed before that.  I'd like to rebuild Shibby's Tomato with all the fixes in the DD-WRT codebase.  Is that possible?  Does Shibby's build files and sources live in a repo somewhere?  Are there instructions on rebuilding it?  How likely would such a build brick my router?  Or not be stable?

My motivation for doing this was to extend my guest network using WDS.  I previously had my primary wireless network using WDS.  But one and possibly both routers will be placed in unsecured locations, so I was going to utilize WDS for the virtual wireless guest network.  That did not workand I even tried the approach in a blog post using brctl commands in the firewall script.  My router has a ton of configuration, mostly DHCP Mac Address/IP mapping.  I did do a standard backup.

The next approach was to make my secure primary wireless network, the virtual wireless network, and my old virtual wireless guest network the primary.  The virtual wireless was connected to the primary br0/VLAN, and the primary wireless network, set up as an Access Point and WDS, for guests, was connected to br1/VLAN1.  Unfortunately, the WDS won't connect.  No messages in /tmp/var/log/messages.  This has me stymied

In another post, Shibby apparently adviced a user to clear his nvram to solve a WDS problem.  So I wanted to back and restore as much of the important data as possible.  A script on the DD-WRT site for doing backups and restores seemed to fit the bill, but Shibby's Tomato is missing getops, tee and a number of other commands, plus there were issues with being able to write the scripts temporary files.  That has become another rabbit hole, as I attempt to rewrite the script.

Any help would be appreciated.  I have been banging my head on this problem for weeks now.