I acquired a 350 lb anvil that fits the description of early Hay Buddens in A.I.A.  I can find no definitive markings but all the dimensions and handling hole location match Postman's descriptions. 

It came on a cast base that it fits perfectly.  Did Hay Budden ever make a cast base?  Some say no, but I'm not sure.

Notice the small 3rd handling hole under the heal, very indicative of a large Hay Budden

Edited September 10, 20187 yr by Jacksman
misspelling

I have a small 114# early Hay-Budden with a base that looks identical to yours.  Mine has a 4-digit serial number which dates to 1913 (2nd year or production) and has plenty of the factory markings on the side to positively identify it.  I've had one other early H-B with a similar base, but can't recall if I have any pictures of it or not.  Sorry the pics aren't great...just took them before I headed to the house to pull out AIA and check the serial number.

 

 

To be clear, I think what you're calling the "base" is what we would call a "stand."  If you're asking if Hay Budden ever made a cast-iron "base" then people will think of the bottom half of the body where the waist blends into the feet. That's the "base" of the anvil.

Did Hay Budden ever offer a cast-iron stand? I don't know, but that's a different question.

Yes Hay Budden did make stands for their anvils, there were several threads about them (anvil with original stand) sadly the threads were before the forum upgrade and the pictures were lost. I don't remember if the stands were marked though. Yours does look like the one's I remember.