Can I replace my Thai marriage certificate at any Amphur in Bangkok, and what do I need to bring?

@Steven **************

You can get a copy at any of 928 District Offices (878 Districts in the Provinces + 50 Districts of Bangkok Metropolis) throughout the country

You can also get an English version of it issued by the District Office (even Red-Stamped English version)

As for what you need exactly, at least your passport.... having your Thai wife go along will probably make things go smoothly as most documents are based on a Thai citizen's records per se....