Looks like #25 in this exploded viewhttps://www.mycnhistore.com/us/en/caseih/na/tractors/agricultural/under-100-hp/case-ag-utility-tractor-prior-to-sn-8262800/power-train/swinging-draft-arms-before-sn-8211729-eagle-hitch-tractor-prior-to-sn-8262800/cn/A6C3B762-8FBF-E111-9FCE-005056875BD6 is the piece you have pictured. Looks like a PO removed the adjustment part, the yoke in the exploded view attaches to. The adjuster probably failed, and they replaced it with what you have now.
I'd look that part over pretty close for a part number cast into it. Case was pretty good about doing that. Then search Google for the number you find.
Otherwise, if you plan to keep the tractor, look for a parts catalog for it. I'm assuming it's a agricultural/utility model, and not a Construction King model. I did a quick look on ebay, and found a reprint of the parts catalog for the Ag. model. I guess not a bad price for a new catalog, although some reprints I've gotten, the scannning/printing process could be better.
Case Model 53? Series Tractor Parts Catalog Manual A4?3 | eBay
If you plan to keep the tractor, using the part number is the key to finding any parts for your 530. Most salvage dealers, and aftermarket part suppliers use the part numbers in their listings. As one part may fit different models, such as in this case,a 430 also.
I'm not sure how much this will help you, but here's a site that has several parts catalogs for the 530CK.
Case 53?CK - Manuals Pretty much the same 530 Utility chassis, transmission, and engine's, whether gas or diesel. You'll have to look through them, as many models did have 3 pt. hitch, and were a popular item in that era, to have a loader, and using a Gannon box blade to finish grade in housing developments. This was a transition era, where they used an Ag. utility tractor for industrial purposes, just modifying them with heavier front ends, manual reverser's, etc, before going strictly with industrial models, bringing out the 80, and 90 series.