Looking for clarification on applying high level module credit

[Stumondo]

My Wizard is one game away from level 12. I've always assumed I'd play Eyes of the 10 with him.

Years ago, I played Rise of the Runelords. We used non PFS characters, and we issued chronicles as per the rules. I applied some of the earlier ones to my character. The next one I have is for Level 12-14. Since normally you apply the credit when you reach the level you earned it at, there's no chance for confusion. But in this case, there's a level range given, and since we were not using PFS characters, there wasn't a specific Level where we earned the chronicle.

My question is can I opt to apply this when I reach any of the 3 levels (12, 13, 14), or does it have to be at 12.

The only reference in the Guide is that you apply chronicles in the order you get them, but I think that would only apply if I had another chronicle at one of these levels, which I don't.

[GinoA]

I'd treat like applying GM credit. You apply it at the lowest legal level. So, 12 in this case.

[Starglim]

The rules are clear that it applies at 12, as it's your oldest unapplied chronicle and at that point you qualify to apply it. Can your GM of the time amend the chronicle for a different character?