A recent post had me digging through my archives to see what I had of "before and after" pics of buffalo. I'll post these pics (and take the heat) and would like to see what others have of these types of pics. While not an expert, I'll give my best guess of age based on being around cattle all of my life.
This was my first buff. Unfortunately, I don't have any before pics of him. I estimate him to be 4-5 years old and not a great trophy.

This buff I would estimate to be 7-8 years old. He was shot out of a herd in the Selous.

He is the skull on the right in the following picture

The bull on the left above I would estimate to be 10-12 years old. He was a loner with virtually no teeth, was very thin and on his last legs. I had to shoot fast or my PH would have shot him. (Just kidding Leon).
Here is a pic of him before. Note the dewlap, roman nose, and drop.

None of these bulls were over 40 inch spread. If anyone else has some of these "before and after" pics and can age the bulls, it may give us all a better understanding of what to look for "on the hoof".

I aged a bunch of them (actually I just helped!) and I think the oldest was 10. They probably don't live any longer than that.

My first buff was a youngster on that last-day-of-the-hunt hunt, and shoot or go home empty handed. I shot!! He sort of looked like yours after the soft boss tissue got boiled away.

The only mistake you made was not to have the taxidermist pile on the fake boss like the ones I see at SCI.