Hi Jeff - welcome to iKC! I don't think I know any more about your Van Sickle knife than you do - sorry.

I know of them, and about Frank. It's hard to live in Texas and not know about him if you hunt, fish, or collect knives. Your knife was one of several popular field designs that Van Sickle Cutlery produced (and my favorite). If you are not aware - Frank passed away back in 2022 from an accident at his home in San Angelo, TX - unrelated to his knife making. Here is the link to his online obituary if you want - https://www.harper-funeralhome.com/obituaries/frank-l-van-sickle-iii

I know that his wife Linda who used to manage the business was planning to shut down the VS Cutlery - I do not know if she actually did, or sold the business. 

In terms of worth - your guess is as good as mine. I would imagine it's value today is a pretty penny - as it is a discontinued model of excellent quality - your's looks to be in mint condition as well. 

As I stated, not much in terms of what you're looking for, but I hope it helps a little.