Hello everybody,
I have a nice 12x16 dot matrix panel that I want to make touchable for my little sequencer project but can't source a touch screen with matching dimensions ( 4"x 3,5" ).
This supplier has a very close match ( model ATP-057) but I can't get a hold of them:
http://www.dmccoltd.com/english.
I've found a few 7" tablet touchscreens on ebay ( Item number: 250668364086 ) and was studying to possibility of trimming them down.
I can afford a little loss of resolution as I only need 4bit accuracy
I would be really grateful if anybody could share their thoughts/experiences on this! 
Thanks
Alex