Sitting for years might need a pull start. Would not be the first example of this engine type requiring it after long sitting. At least their automatics can be pull started. Read about the speed required and method in the archives.
Again if it will not light off temporaily with glow plugs and a shot of wd 40 thats about the only hope you have. I assume no stuck open valves from sitting or you would hear the uneven compression.
Also if the car has a block heater heat it up for a few hours before the attempted start either by towing or starter. The additional heat sometimes makes some difference. To loosen up the rings a soaking with marvel mystery oil will usually raise the compression quite a lot. It's cheap as well. Again combine the soaking with the block heater for a few days to aid the chemical reaction going on.