OEM data didn't present any bear traps.
Oh, there be dragons awaiting the unwary in some areas ... probably not too much of a concern now that all the older P-chart folk are dying off, I guess. Having run up a few of the P-charts, I thought the DCA approach was more than reasonable for GA purposes.
his father was first violin in the SSO for many years
Ernest. Of that I was unaware. Small world - until aeroplanes interfered with my plans as a younger chap, I was heading towards a career as a professional flautist (a student of Victor McMahon in Sydney). A number of my schoolboy buddies continued on with instrumental work and ended up in this and that SO around the country. Ah, the most fond memories of the Sydney Con ... but let's not go there so that the guilty be protected from their youthful inappropriatenesses, as it were ...
.
Re. the Aero Commander 500S
I have no current knowledge of the situation. However, the basis for the recertification was component comparison to heavier airframes with whatever changes were required and the GW ending up limited per the ANO 101.22 OEI climb requirement - made a useful difference VFR ops. The US basis was, as I recall, the climb limited requirement. On a like tack, I did a similar recert for the 500A some time later and on the same basis. I fail to see that there would be any real concern regarding the increased weights from a point of airworthiness signficance ?