This is my opinion, but seems to be one I have learned by consensus over many years at car shows, auctions, and other thoughts expressed by those in this hobby I have come to respect.
There may be four categories a restored/unrestored car can fall in to:
1. all numbers matching
a) bears authenticated VIN. By authentic, I mean the dashpad, door sticker, body sheetmetal stamps, body code plate, broadcast sheet and title VIN numbers all match the same 13-character number. These numbers have not been altered, and do not appear to be over-stamped or counterfeit.
b) the motor type is a motor matching the type of motor encoded in the VIN.
c) the drivetrain is numbers matching. By matching, I mean the partial 8-character VIN stamped on the engine and transmission match the VIN. A numbers matching car will also be motor matching.
d) all options matching. By matching, I mean the options the car is presented with correlate and match (and corroborated by) the body code plate and/or broadcast sheet. If a given option was replaced by an aftermarket duplicate, for any reason, I believe this still counts as options matching. This is common during restoration, and in some cases, is difficult to prove one way or another.
2. not numbers matching. This is pretty common as during the life of the car, engines get blown up, transmissions replaced, and so forth. In some or many cases, this change is involuntary and unavoidable.
3. not motor matching. The motor type does not match the type encoded by the VIN. The VIN telling you the motor type is unique to Chrysler products, and I don't think it's found in GM or Ford cars. But this is a voluntary deviation from the factory original motor type the car was originally made. This becomes a "tribute car" and can be an original 6-cylinder car with a 426 hemi bolted in. Anyone can make a car like this. They need only to have deep enough pockets. To argue this is just as valuable as #1 condition, means we reward those with bigger budgets.
4. not options matching. This is another (in most cases) voluntary deviation from factory original. Just because someone gets lucky, and finds a cute option at a swap meet (example, rear window louvers) doesn't mean they can bolt it on, and claim the car is now more rare and more valuable, just because they bolted something on. Again, we don't reward people who fake things by deceptive means. To deviate from factory options also seems it is just like the "tribute car" scenario. Sadly, when a car is missing BOTH its body code plate and its broadcast sheet, there is no reliable way to tell which options came with the car, and which ones were bolted on later. So a car missing these items falls into the "tribute car" category, because there is no corroborating evidence to the contrary. Pulling a body code plate and/or broadcast sheet from a car that is still on the road is a pretty sad maneuver.
Condition #1 is the highest value condition the car can be in. It's a debate if it's worth more restored, versus unrestored in nice condition. Maybe it's worth a little less if it needs restoration, body work and paint, etc.
Condition #2 is slightly less in value, than the top condition #1. How much less? Arguable, maybe 5% less.
Condition #3 and #4 is a mixture of factors when calculating a car's value. The value of the parts themselves comes in to play. But for the most part, the sum of the parts is not greater than the whole. In other words, two cars, identical in every way, the car in condition #1 is more valuable than a car in condition #3 or #4. How much more? Another topic of debate, but at least 25%. The more rare the options, the greater the percentage over #3 & 4. I seem to recall a condition #1 1970 Hemi Cuda selling this year for over $1,000,000 at Mecum.
Sadly, as Condition 1 and 2 cars increase in value and get further out of reach of most budgets, cars in condition 3 and 4 become more profitable to make and sell.
So, back to this beautiful 440-6 car. It's either condition 1 or 2... or it's not. If it is, it's worth close to or above 100K. If it's not, then less, maybe closer to 75K.