Error coin, nice! You should share some pics. There's nothing on the coin or it's hologram label hologram up that is sensitive information.
I've never sold a Cas coin, only bought, but i've followed the market quite a bit over the years.
- How do I make contact with an Escrow, and who to trust?
Here's the list of reputable escrow providers:
★LIST★ BitcoinTalk's ESCROW Providers
- How do I prove my own trustworthiness and coin legitimacy
You need to provide pictures of the coin - both sides, high quality, the more the better. In the past people would get these coins graded but i'm not sure that happens much anymore and it's not required for you to sell your coin.
There is a site where we can verify that your coin is loaded with BTC, just go to Casascius.uberbills.com and enter the prefix of the address found on the hologram. This will verify that the coin's address still contains BTC.
- How do physical hand-offs work in Corona-time?
Latest health official guidance is that coronavirus can't contaminate objects as originally thought at the start of the pandemic. BUT...buy a plastic coin case (from any coin shop) to put your coin in if you want to protect/preserve any germs from getting on the coin. Allows anyone to sterilize the outside of the case as they deem appropriate.
- How long should I expect it to take?
This is a big sale, be patient with the timing. The escrow provider can also help you with writing the post or running the auction, if you want them to. Most auctions come with a duration, however you could set a minimum sale price at the start to ensure your upside.
- What scams should I look out for as a noob?
Don't buy or sell via eBay, nor in person. eBay is easier for sellers but you aren't totally protected from not getting paid. And if you meet someone in person you could get killed...there were stories years ago about people getting robbed when meeting in person to sell bitcoin.
If you keep your deal at bitcointalk and use one of the reputable escrow providers you'll be in good hands.
Personal Thoughts - the error coin could command greater interest because of its novelty, first issue and error status. I would test the market with an auction that has a minimum that's high enough for you to cover the fork coin value and whatever premium you want. This protects you from taking a loss (from fork coin value) if interest is low. You can always strike a deal with the highest bidder if that person came close to hitting your minimum. If bitcoin really goes the distance i believe these coins will be be truly collectible in numismatic circles, and if that day comes I'd use a Sothebys or something equally official to run the auction.
Welcome to the forum and good luck to you!