Where can I find previous stable release firmware?

firmware.ardupilot.org only saves latest dev build in historical
github.com/ArduPilot/binary/commits/master is missing a few such as copter 3.5.6-3.5.7

Am I missing something glaringly obvious?

While I am ranting, and since I have been unable to find a reliable source for old builds (unless I save it locally myself while it is latest from firmware.ardupilot.org) I am forced to tinker with new parameter changes such as batt_amp_pervolt to batt_amp_pervlt (WHY) so my saved parameter file can’t reliably get me close to flying. I don’t mind tinkering every once in awhile, but being forced to update to new firmware when I change hardware is frustrating.

/rant

Seriously, can someone point me to a reliable source for downloading past stable releases?

They are on mission planner.

MP%20Firmware%20List
From what I can see some are missing. AC3.5.7 AC 3.6.0-3.6.1.
I have also had errors in the past when trying to use this drop down. This seems like a labor of love to keep this list updated. Perhaps an automatic repo when a stable is released would be nice.

3.5.7 is there. I don’t know what the criteria is for not having the others.