where to find old firmware?

Hello there!

Today my TV discovered a new firmware release, and it's begging me to install it every time I turn on the TV.

However after reading the experience from other Philips users, I would like to have an installer for my current firmware version before proceeding with the update. (So that I can downgrade back to my current firmware in case its getting worse)

Where do I get older (but mostly working) firmware images for my 40PFL5007K? (I'm currently on version Q554E-0.79.4.0)

Thanks in advance!