Searching for replacement parts for an aging game console controller

My general question ... where do you folks go when searching for replacement parts for aging technology, particularly pertaining to game consoles? I've come across iFixit, and of course there's Amazon and eBay as well, but I've been having some difficulty finding a particular part.

My specific issue is, I have an old Dualshock 4 (model CUH-ZDT2U, with PCB/motherboard model JDM-055) that is on the outs. It started experiencing some stick drift, so I took it apart to clean the contacts in the joystick housing to the best of my ability. In doing so, one of my kids managed to get a hold of the controllers' guts and break off the vibration motor wires from the board.

So, after taking the board and chassis to a local Makerspace, I got the wires soldered back onto the board. So far so good! However, the stick drift is still an issue and the vibration connection isn't that great. So now, I'm hoping to find some replacement parts - namely, a replacement board with the chassis and motors included.

One of the main reasons why I'm trying to refit this old controller, rather than replace it outright ... is because my wife bought the controller (and the PS4 it came with) as an anniversary present years ago. I'm the sentimental type and I'm trying to keep as much of this old controller going as I can, Ship-of-Theseus style. In addition, these controllers don't come cheap - $70 seems to be the basement these days for a new, in-box controller.

I've taken a swing at purchasing replacement parts off eBay - however, while the controller models matched, the board models did not. iFixit has the exact parts I need, but they are out of stock and their stock is inconsistent. I found another site - Fasttech.ca - that purports to have the same parts, but looking around online I've found a fair bit of discussion surrounding this site and the fact that it may be less-than-reputable.

Any advice on where else I might be able to look for parts?