Not sure if this has come up over on the sub before, but LynchNW recently released yet another Spyderco clip—the stubby. I’m completely happy with the MXG style, but this is probably the perfect one for those 53s for those of you into the classic Spyderco look!
This is the one I use. Fits great, is fairly low profile and isn’t too long.
https://mxggear.com/collections/paramilitary-2/products/custom-made-titanium-deep-carry-pocket-clip-for-spyderco-knife-23
Here are some pics, look at the 2nd and 3rd image (first is a Lynch clip made for the McBee that did not fit the hole pattern).
https://imgur.com/a/UMoo8SD/
I really like it on the SC64 as well, have a plain Ti on mine.