I just recieved some information from a very knowledgable friend on this subject.
First off - the attachment which I mentioned earlier was called the Aqua Queen.
More importantly, Filter Queen actually DID make a wet/dry machine. It was the model 530 and was put out during the mid 1950’s. It came with a rubber hose, and a float that went into a 5 gallon pan.
So I stand corrected. Thanks for the help T.
Doug