Got home a while ago, unpacked the bags, had a bite of supper, and thought I'd post up my thoughts here but WOW! you guys are quick.... the points have all been pretty much covered by Dave and Rick. And I concur with them. With one small exception: since this was a "mule" car, and there is no tangible documentation presented on its original configuration, it would be difficult to ascertain whether or not the Chevelle began life as an SS396. The "136" VIN however, would infer that it could be either a Malibu or SS (396 or 454), but w/o the presence of original VIN-stamped drivetrain components or a build sheet, there's just no tellin'.
As for the '69-style master cylinder and p/s setup, there's no way to confirm that they were installed at the factory either. But by including them as part of the restoration process, their presence easily becomes palpable evidence that helps make #42's story more believable. There was no information offered on the rearend, either, as to casting #s and dates or the axle tube stampings, so it's difficult to confirm what may have been the original third member.
I had a good visit with both the owner and restorer and learned that the "42 of 49" part of the story stemmed from a conversation with Richard Downing (GM exec), who also allowed that was one of "only 10 or 12 Chevelles" to find their way into the hands of public consumers. At this point I believe they are aware that in order for #42 to fully realize its historical and financial significance, it's imperative for Mr Downing to confirm the context and content of that conversation in written form.
As for the Chevelle itself? I think that it's a very nicely restored Chevelle. What's it worth? Same as any other transaction.... It's worth what one person will pay, and the owner will accept. At some point in time, when and if the Chevelle ever changes hands, I'm sure we'll all get to learn what one person paid.....
And finally, if you haven't attended the MCACN show, you owe it to yourself to make the trip. The diversity, rarity, and quality of the cars there in attendance are sure to make it worthwhile, no matter what your interests may be. Even better yet are all the old friends you'll get to see and all the new ones you'll add to your list. I know I really enjoyed the time there this past weekend, and truly appreciate the (old and new) friends who were kind enough to share their time with me.