Any thoughts or opinions - other than "just box them up and send them to me" - are appreciated.
Some people "never" sell a gun and I get it.

I have had guns I wished I still had (SKS, SS Ruger Redhawk .44mag with scope).

But I am not a "collector" and some collector-type guns have been sold to fund new guns I will use.
For example: Last year I sold a S&W 622 "target" (6" barrel) .22LR semi-auto pistol I had for about 30 years. I was not the original owner but it was "like-new" when I got it and when I sold it. It got used maybe once a year and the kids learned semi-auto pistol and marksmanship on it.
The proceeds bought a SIG P322 .22LR semi-auto pistol which gets used all the time. That gun has controls in the "usual" places and also a cheap red-dot. With three 20rd mags included, I use it every so often at the monthly Action Steel matches I go to. Those matches will usually burn 150-175 rounds. So $15 of 22LR vs $40 of 9mm.
Anyway, I have an "agreement" with the wife that my gun hobby must be "self-supporting". And it is for the most part. But I'll "sneak" $250 into my "fund" once a quarter to buy 1000rds of 9mm.
I'm drawing a blank as to what state you live in--Kansas or Nebraska? Both are decent 2A states so no "Universal BGC" required. A sale locally, face-to-face would not require by State or Federal law any kind of recording or checking IDs or any of that. But you
should have "rules" not unlike an FFL but without the call-in to the FBI/ATF. I don't deal with anyone not willing to show ID or fill out a bill of sale. Lately I just take a pic of their ID but do not check their background. You can usually tell if someone is a scumbag on the phone and not someone you should be selling to.
If you wanted to maximize profit, create a GunBroker acct and market your guns on there. You will need to be able to send the gun out through a local FFL. GB will have a "list" of affiliated FFLs in your area and you can get their contact info and ask them how much to ship out a gun through them. My guy charges me $20 to ship a pre-packed firearm. All he has to do is check the serial number, record it, then seal the box and put a shipping label on it (that I provide). The buyer pays these fees when they win the auction and check out.
PS: consigning isn't a bad idea. I'll assume your guy gets 25%? What you should do first is go to GB, enter your gun make/model and see what they are selling for. Go to "advanced search" and select "completed listings". That way they will show you actual market vs what a seller "thinks" the gun is worth...
Hope this info is helpful and you are welcome to PM if you want.
PPS: I had a nice simple gun BofS but I can't seem to find it. I found the attached, maybe it will help...