BTW - I think it's more that the table was made to fit the wood base for the cased models (I've seen both 15's and 201's as "portable" machines). This base is just a tad narrower and a lot shorter than those used for full size Bentwood cases.
It just so happens, that the bentwood base for the 99 and 128 is about the same width and short enough to also fit in this size opening.
On a side note - I am usually pulling out old photos in my photobucket account - and it's funny to realize how much I've moved stuff around in the last few years!