Hi Claudel
The 1400-hr life limit was intended to apply to IO-540s fitted to sport aerobatic aircraft such as Extras and Lasers. It was always ludicrous to apply it to the Don Marchettis because their aeros, whilst vigourous enough, weren't remotely as hard on engine life as those of aerobatic aircraft.Certain persons in Baldonnel decided that it applied to the Marchetti engines,as well.We were tearing down those engines at 1400 hrs and finding them well within wear limits/oil consumption limits,etc.
As for the firing circuits,no civil servant will allow those items to remain in place for a civvie to buy them.I'll bet they will only be allowed to remain in place if a foreign government buys them.
regards
GttC