ta-082 2.81 downgrading

As mentioned in the title I have a ta-082 with 2.81 FW. I've read that its possible to update and then downgrade to 1.5 but I'm not sure I have the right LCS. I can't find what version it is and it doesn't say anything on the UMD for the version number. I've read other places that its able to be done using Lumines, which I have. They didn't link or give any type of tutorial so I'm sort of stuck which is why I'm asking here.
Any help would be appreciated.

Yup your correct... Anyways when you have your GTA:LCS game umd inserted it will show 2.00 in the game update if it is unpatched and 2.60 if it is patched....you need the 2.00 to be able to downgrade. Picture below..


3.03 downgrader
http://www.pspbrew.com/forum/viewtopic.php?t=7034

3.50 downgrader Lumines needed
http://www.pspbrew.com/forum/viewtopic.php?t=8427


Once you have successfully downgraded to 1.50 i suggest upgrading to custom firmware 3.03 oe-c or 3.40 oe-a

3.03 oe-c
http://forums.afterdawn.com/thread_view.cfm/460892

3.40 oe-a
http://forums.afterdawn.com/thread_view.cfm/500493

Once this is completed i suggest reformating your memory stick so the new folders will be created for you autmoatically.

Ok I downgraded and upgraded to 3.4 oea using lumines and the great guide here.
One last question - Is there a cheatdevice that works for LCS on 3.4?