The store owner is most active on Facebook and posts her new finds there. I'd reach out to her directly via Facebook Messenger.
I haven't had things appraised there but my guess is that you could upload pictures and attach them to an email and find an address on their Facebook page. When I went shopping there I did see people bringing furniture by in their vehicle and doing the negotiation right there. So I suspect that's an option too. But they may have made an appointment.
The fastest way to contact the owner is through the social media for the store
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