apushatayid –
The OP is certainly asking a fair question. She has done her due diligence and called the number and she got no answer. She doesn’t know who this rabbi is, so it is quite responsible of her to ask the question on a public forum which can help produce facts. Anyone giving a hechsher should be real about how well-known they are in the community, and if they are not, and they expect to be accepted by responsible people, they should make their credentials accessible one way or another.