I have converted a Canon A480 with the Rosco #2007 filter so that I can (hopefully) do some comparisons with it compared to a Tetracam ADC Micro. I also have a Canon A2200 that I intend to modify with a Wratten 25a filter, although I am struggling to find a filter for it at the moment (anyone have any spare?).
Converting the A480
The process to convert the A480 is almost exactly the same as the A490/A495 with two exceptions, one which makes it a bit easier, and one slightly harder.
You do not need to unplug the button pads ribbon cable to move the LCD display out of the way (it only has one cable rather than two attaching it to the camera).
When removing the sensor, there are two very small springs under it that will mostly likely ping out (see the picture for where they are), so watch out for them and make sure you remember to put them back in again.
I found the conversion to be fairly easy, especially after following the video for the A490/A495, its just the springs that were unexpected. I haven't taken a shot outside with it yet, but once it stops raining (it does that a lot in Scotland) I will be giving it a go and will start posting my results.