The B model P3 Orions had a cumulative counting accelerometer fitted in the main electrical load centre just about over the main spar. As I recall, it recorded g counts in .5 increments up to about 4.5 or 5g. After each flight maintenance recorded the new numbers and they were used to monitor the life of the aircraft. No doubt there are better systems out there but maybe Lockheed could help out based on that old system? It was simple and it worked.
cheers