Unfortunately I cannot be certain if it is still compatible with current labscript. It also only appears to be the labscript side of things - I could not find the corresponding code for controlling the hardware itself. It's possible it is in the BLACS repository history somewhere (as it appears to predate the creation of labscript-devices) but it also may not be.
The simplest existing devices to look at are probably the PineBlaster and NovatechDDS9m in the labscript-devices repository. They implement a pseudoclock and an intermediate device (something clocked by a pseudoclock that has Digital/Analog/DDS outputs).
Alternatively, the PulseBlaster might also be useful as it (as well as being a pseudoclock) demonstrates how you create a device that is a pseudoclock with directly attached outputs (by internally creating a fake intermediate device). Which of these is most useful depends on how the Adwin Pro II works.
I'm not familiar with the AdWin Pro II, but it looks like it is made up of multiple modules. If all modules are programmed through the one PC interface, then they probably all need to be in one labscript_device class (at least for the BLACS code) but you'll probably want to start with just writing code for one module. If you can provide the model of the module you want to start with, that might help direct further discussion and I/other mailing list users may be able to provide some more specific guidance on where you should start.
Hope that helps!