Q: Are there journals which would publish identities of classical functions?

A:  Elsevier's *Applied Mathematics and Computation* has published quite a number of papers in that category, see this <A HREF="https://www.sciencedirect.com/search?qs=identities&pub=Applied%20Mathematics%20and%20Computation&cid=271588">search listing</A>.

It is ranked as a Q1 journal, open access is optional.