Welcome to the forum, Larry.
Not many people in Britain these days sign their letters using post-nominals with their signatures. If you wish to do so, however, you could put:
Larry Moore BA BSc
Larry Moore, BA (Hons), BSc (Hons)
On my business card in the Czech Republic, I give my highest-level degree, because that is expected here. I don't use post-nominals in Britain.
- For Teachers