Test the waters. See what they're willing to pay. If you feel their offer is insulting you can always walk out of the place.
I thought the vertical lines were actually caused by the process that adds the edge lettering so they may not be present on actual error coins. Odds are that these are post-mint damage since there was such a fever to find these, but you never know. I have one in the safe, but I can't remember if there are vertical lines on it or not, and it is hard to see since it is in a PCGS holder. Congrats if they are real. Even at $25-30 that is a nice return on a dollar.
In the condition you're showing (based on the photos) I wouldn't think anyone would give you more than $5 each. There are thousands and thousands of these Washington no-edge-lettering dollars. NGC alone has graded more than 42,000 of these, the lowest as AU58. There are likely hundreds of thousands of these in rolls, circulation, and in mint vault bags. Certified MS64 examples have sold within the past year or so on eBay for around $40 or less.
Millions of missing edge letter dollars out there. A US Mint security employee was convicted for the theft of MILLIONS.... read that again- MILLIONS of missing edge letter coins. So the idea that they are a rarity should probably be printed in vanishing font on the labels by NGS, PCGS, ANACS, and the others encapsulating these gems at a tidy sum.