Better get on the stick. That is a VERY lucky find!!! Seems to have all the scraping marks underneath it. Hopefully these are accurate,and not a left over from someone trying to learn scraping. In any case I'd grab it. A few trips through a larger mill can get all accurate again,if needed. I had to have my #4 recut. It had gotten curved down from years of having T nuts tightened in the T slots. Had to be milled on top and all bottom surfaces.
Great ! I hope the table fits. I am not a Burke historian. Is the top surface convex?