Large Art Pottery Bowl - Walter Dexter?

Hi

There is a mark on this large glazed bowl, but other than the rectangle outline it isn't possible to make out any characters.

If you were to Google search: Large Art Pottery Bowl Signed (Walter) Dexter; 8 3/4"   you would see another bowl in the same glaze, same colours/finish, except the finish on this base is different (glazed too) and the other one is unglazed and signed Dexter.

Could Dexter have finished it for another potter, if so does anyone recognise the bowl/rectangular mark, or is the glaze just coincidence?

Thanks

I don’t think Walter Dexter is the only one to have used this glaze combination. And it’s unlikely he would have collaborated with someone else unless they were an apprentice. I’ve only found pots of his signed Dexter