Repeter, I did not know that, I always pictured you as a young dude! I suppose that is a good thing though. :)
Regarding reporting your gains, I think it is fair to report the full amount. Maybe with a caveat if going into detail about them. But I think your hard PE work is valid even if it was producing mainly a combination of newbie gains and reclamation of youthful size. To me it would be like someone not reporting their fast initial gains because they were mainly attributed to newbie gains. You worked for all of it, be proud. :)
To both of you, I don’t know a ton about the effects of aging on the size and function of the penis specifically, but I can speculate. As Austfred mentioned, hormone levels decline relatively quickly each year after about 30, that can cause a decrease in EQ. Circulatory efficiency decreases a bit with age as well and this could have a similar effect. Then you have the things that contribute to ED like the build up of intracavernosal plaques and decreased smooth muscle tone and these things are also correlated to aging. So all the things I just mentioned could be working in some combination to decrease EQ and thus penis size. Also, connective tissue becomes weaker but also more inelastic as we age, this would reduce penis size as well as the tunica would have less ability to expand under pressure. Also, either of those factors, reduced EQ or inelasticity would mostly effect erect size which goes along with Austfred’s example.
The good news is that, as you have both discovered, the most acute effect of PE is improved elasticity and EQ. When these things are lacking, that can translate into very fast size gains.