It wasn't me. The former owner did it. My old Craz rack just has those big spikes coming out of the frame. What was meant to be on the Craz 3 rack? I didn't even check. I will say this, the new SRA rings a lot more than the old one if you rap your knuckles on the shelf.
I believe there is a new footer design that incorporates the shelf material with spikes like what are probably on your earlier model. Unless the previous owner re-bored the threads, you should be able to return to stock. The thing is designed to be used as comes out of the box. But it may be too much hassle to de-platform all your gear.
Yes wrt to ringing - I've heard something like that from others - Marc Mickelson reported the shelves on the version 2 "felt and sounded (after a light tap) unusually lively -- bell-like almost" although he thought the new ones were more inert. Maybe you have v2 shelves? You can also get the 'iso-pads' replaced for each shelf (no charge) to match what's on them - just tell them your gear and they'll send what's appropriate - it only takes a screw driver.