I've got common parts kits coming from RA, no solid ETA though.. That'll take care of some of the smaller bits.
With that low a SN, you probably don't have any of the updates. If it shoots fine, I'd say keep shooting it until something breaks. If you are interested in updates you've got the trigger, bho, safety, mag release, gas block, op rod and I'm guessing bolt/firing pin too. The newest BCG requires machining to the lower for the update but there's an update before that was a drop in.
If you've got the original style (tool required) gas block, I'd recommend getting a new barrel with an updated block on it. Gas ports on the original barrels were larger than current spec. If you update the gas block, you'll need an updated piston head or complete op rod. There's a few flavors to choose from on the rods.
Check the links
https://www.xcrforum.com/forum/12-tra...nversions.html (contents of the CPK listed in the first post)
https://www.xcrforum.com/forum/15-fie...s-options.html (list of most of the upgrades to the XCR-L)