I went here for full instructions:
http://www.math.ias.edu/~tarzadon/pages/posts/droid-2-r2d2-sbf-97.php
Jumped straight to download mirrors here (from the instructions above):
http://mir.cr/1KUWDQWP
I used this set to download the 2.3.3 sbf over the weekend, flash back to unrooted stock 2.3.3 & perform clean OTA update to 2.3.4 ...
Used the "deposit files" mirror for sbf download, used RSD Lite (Googled latest version) & successful on first attempt.
Now I also waited way to long in bootloader mode with a low battery while downloading the sbf etc, so I destroyed an old standard printer USB A/B cable to hack a battery bypass while RSD Lite flashed the sbf. (That's a whole 'nother story!) It was not pretty for a while, but it was either that, obtain a charged battery, or sit on looped "low battery cannot program" error. Resuscitated from possible BRICK status, "Eep!"
Learned a lot over the weekend thanks to this forum & other sources. All prompted by the OTA push to 2.3.4 popup end of last week. After all this, I've had no force close on browser, no random reboot (after previous 2.3 OTA it would reboot on shutdown, media dock & car dock with no warning), no more SMS thread splitting/duplication, and I haven't experienced any audio/notification silenced issues that others may have seen.
Best of luck if you go the same path I did. Regardless, this was how I found the legitimate R2D2 2.2 sbf for my actual Moto A957...
Yes I intentionally wiped out my root with this method. I wanted a fresh start, now just patiently hunting for new root access to be revealed (so I like it "mostly stock," it's a problem, I admit it!)... 1st thing I do after root is rename R2D2's "Spunky Attitude" ogg in system\media so that stock bootanimation script doesn't find it on boot...
K
Probably brave enough to try custom ROMs now, but ...nah.
End Transmission from R2D2
EDIT: I said stock 2.2 but meant 2.3.3 sbf (*derp!*), which Pete's Moto Root Tools _can_ handle. Whoops! I quit looking for 2.2 sbf when I found this stock 2.3.3 sbf ... sorry to spread confusion if I did. Eep! ... now dreaming of 2.3.4 root following the successful OTA sans root.