As most of you know, sus 4's are no longer available. This seems like an obvious fix but here goes. I removed the original mount, cut a piece of 1/8" thick steel, 1 1/4" square ( original mount is 1/16" thick, I doubled that for strength ).I drilled 4 holes to match the original mounting holes. I drilled a 3/16 hole in center of steel plate for chassis mounting screw to pass through. I painted it to prevent rust. I mounted the steel plate to the underside, same place the original plate was mounted. I used mounting screws that were 1/32 larger in diameter for better bite. I put 3 rubber washers 1/8" thick in the top hole resting on the mounting plate. Then I put the original steel washer on the rubber washers and used the original mounting screw to attach the chassis to the cabinet. Although this method doesn't have the same shock resistance as the sus 4's, I was surprised at the shock resistance it did provide. Also, it pretty much retains the original look although the cabinet holes are 3/8 shallower due to the rubber washers. I suppose you can omit the rubber washers if that's an issue for you but that didn't matter to me. I hope this helps somebody else that is unsure of how to fix this problem, as I was, without replacement parts available.