Looking good! I do something similar, but I use a discarded 18 wheeler brake drum- - - - -which weighs about 100 pounds, and anchors whatever implement I mount on it very effectively, but it can be tilted and rolled anyhere in the shop it's needed at the moment. A piece of 4" schedule 40 pipe and a steel plate on top completes the assembly.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!