A very old version of Robbit, specifically "Delicious Doughnut" Patch 25.2 (r3242), has now been made available in Robbit Launcher 3. This version of Robbit is the final build of Delicious Doughnut (based on Minecraft 1.6.4) and was previously released on 27 July 2014.
This old version of Delicious Doughnut has been made available to provide full backwards-compatible map conversion for some legacy map files, since Eclair and Fondant branches are currently only able to open maps saved in Doughnut 25.2 or later, whereas the Doughnut branch is able to open map files all the way back to the earliest versions of Angel Cake. You can therefore use this version of Delicious Doughnut as an intermediary in order to convert maps from Robbit versions earlier than 25.2 to the Exciting Eclair stable legacy version or to the very latest Fondant Fancy bleeding edge builds.
There will be no support provided for this old version. I did however test it to make sure it correctly installs and launches.