Check the 14 Martin for cracks, small hairline, looks like a scratch, cracks where the handle joins the pan. A common problem with the Martin 14. I have had several examples that have this issue. Looking at the upside, the hairline will appear on the right hand side. Small, undetectable under build-up (crud).
Hope yours is solid. Check very carefully. I hope your example is solid. Even if not, we ( the wife and I) have used a hairline cracked 14 Martin for deep dish pizza for years. The crack has remained the same.