I've dealt with Liberty Coin Service more than once. The few times I've done so, I've been in their showroom in Lansing; I've never dealt with them via mail. They have quite a bustling operation. I did pick up a 1916-D Mercury dime from them a couple of years back. It was a nice coin. Wish I hadn't sold it, but the sole purpose of the purchase was to make a profit, which I did. I would have no reservation recommending them.
And Paul is very knowledgeable. I love that place! See my post on Carl Goetz medal. Gave me the option of return or lots of money off. If you are going, LMK I'll go with you. Not sure how they are with ancients, but I'll find out.