Uses common 40 pin LCD connector used by Pi and LCD shield for Arduino. If you can determine the exact type of LCD (size, timing, etc), you could get a bigger one that has all the same specs. Otherwise you'd need to get the DSO firmware, modify it for different LCD (different resolution, timing, etc) and upload it to the DSO chip.
The one I have has convenient programming port on the side. However I don't know how to hack the firmware (or code if you can find un-compiled codes) and load the correct LCD data in it.