Metal Gear Ac!d ! Firmware 1.5

Hello all, i'm new to this. i have read all with great interest.
I purchased a euro psp 1.52. Upgraded to 2.0. I understand no homebrew passed 1.5. However i read today that the euro Metal Gear contains firmware 1.5. Can anybody cofirm this to be true?
Also if this is true would it be possible to install this and change an upgraded 2.0 back to 1.5.?? I would love to enjoy all the lovely emu's and wondered if this was a way without waiting for the downgrade??
Thanks in advance for any info and help!!

metal gear acid doesn't let you install 1.5 unless you have 1.00, so your out of luck