What's the correct use of apostrophe here?

There are two men named Bill Bass. I want to write the following two sentences. I want the two sentences below to refer to both of them, as plural, not possessive. Is this correct?

I think this should be the Bill Bass' Memorial Picnic. That way it can be a memorial to both Bill Bass'

Answer

No hard and fast rule may be possible to state, but generally, a name ending in s takes -es for the plural and where required, the apostrophe comes thereafter.

cf. "the Joneses"

I think this should be the Bill Basses' Memorial Picnic. That way it can be a memorial to both Bill Basses.