Very neat find!
By recollection, the original 630 was discontinued in 1995, but, we know that all three versions of the base 630 had different intro/disc dates and we know that different sub-versions (i.e. the "Performa 637CD" had different intro/disc dates. If any 630 variant actually continued beyond mid-1995, it would mean all the sources we have for intro/disc on them are wrong, and as far as I know it would be the first evidence that this happened beyond ~1992 or so. Other instances of this kind of things are known to almost certainly be case swaps on sub-models that did last longer than the "main" model (such as Performa 476 and Performa 560).
My most instinctive thought is that it could be a 6200 or 6300 case swap, but, still, looks nice! The plastics are probably good. I've got a 6220 and its plastics are solid, so far as I've poked at it.
Incidentally, the Performa 560 lasted until mid-1996 as well, making this not the lowest end possible 68k of the moment.
The 6200 started at like $1299 ish so I've always wondered how much demand there would really have been for a 68k, especially a low end model. This is late enough that the 100MHz 6xx0/5xx0 families would have launched (well, within days of this) and those should have done way better at 68k emulation, and 1996 is getting late enough that most consumer and edutainment stuff would have switched over to being PPC native. Plus mid-late (August) 1995 saw the introduction of the 7200+ (Granted: base 7200 was $1900, so) for people who needed more emulation performance.
The next latest 68k in this family I can find is the 640/DOS, discontinued February 1996. All the 1994 630 variants are listed by EveryMac (and, TBH I kind of bet some of these are wrong) as being discontinued at varying times in 1995. (adding: P588 disc. May , 1996.)
Now I'm kind of wondering if there's a good archive of Apple press releases and if they published discontinuation dates in them. Maybe that's a future project for me.
I'll admit I don't strictly speaking believe the idea that Apple was custom making 630s for some customer who needed a 68k but didn't want something nicer, for whatever reason. They'd make fine ExcelBoxes, but, for what EveryMac says a Performa 640/DOS was selling for ($2400) so would a 6100, 6200, or 7200. (I do realize $2400 probably included the display and at least clarisworks, and might be the /DOS version's price.) It's not impossible, but it is difficult to believe Apple was well-enough organized to realize all of this and receive or make an offer and then do it.