It has been taken apart on the front and back. The blower doesn't show and nuts on the studs. The chipped paint suggests it may have been used, at least the storage methods have been lacking. The front end nose case is missing. They could be set up for P-39 use with a plate here. The boats and pullers don't use the nose case.
What -model is it. He states built between 39 and 41. There could be date stamps on the case which were marked at each overhaul with Total time.
The magneto is the earlier, smaller unit.
I have pulled banks on a new or overhauled WWII Allision and seen tons of crud growing out of the rod and crank bearings. I have also drained new looking preservative oil out and after careful inspection and pre-oiling installed a box engine on an airplane.
Rich