First off, I am very sorry for your loss.
I'm not a fan of entering the picture when a death occurs although, as someone who buys and sells the cars, I often am asked to.
If you need help in getting another opinion on value, Id be happy to give you an opinion. The two names that Bill suggested above are also great resources.
I would also suggest getting an idea from some of our forum regulars who are very focused on 68s in particular. TLEA and Coralsnake come to mind.
I will be the first to say that I dont buy and sell that many 68 Shelbys...I know and follow the market probably better than 95% of the guys out there but I also admit that there are guys who are better than I am when it comes to 68s...so I sometimes lean on them myself.
But I think if you got honest estimates from the various names mentioned on this thread..you will then have a good idea of what fair market value is on the two cars you have. Also it would be helpful to be as detailed as possible with each person who you are asking about the cars themselves...how original they are, the exact factory spec, if they have good original sheetmetal and drivetrains etc etc etc etc etc. You cant give too much detail to someone who is giving you a value estimate like this. For example, you dont mention it (so I assume it doesnt have it), but if the KR is a factory AC car...then the value is drastically different than if its a DMG 4 speed KR vert with no air. A non air car is obviously still a very desirable and cool car but a factory AC car is much rarer and holds a completely different level of value.
Anyway, happy to help if I can...my email is vestes85"AT"gmail"DOT"com.
Kind regards,
Vern