I am not personally interested but have a few thoughts- you'll obviously need to get more info, like whether the Minus K was retrofitted- I use the big bench top externally on the Kuzma XL with Airline; how is demo/testing of operating condition going to be performed- are you going to do that or hire somebody you trust? cartridge for demo purposes? The easier you make it on the potential buyer, the more likely it can fetch a decent price as compared with "as is." That is a lot of work and will cost somebody time and money. There is also the option of consignment which may still involve shipping- not cheap these days, and the widow will take a hit financially, but the right dealer (not me- not a dealer) could do all that at their cost and market it, so it may take the widow to the same place in terms of net return.
Or perhaps this post will generate interest and that's all you need. And what I've said above is simply some blithering insights into the obvious.
PS: if there is any support for this front end that information would also likely prove useful.
Good luck, sorry if it was a friend---
Bill Hart