We are around auction sales weekly, buying and selling.
The one thing I would say is that auctions are like supermarkets they all have a particular market they aim for so make sure your item and auctioneer. If you wanted the cheapest Christmas turkey you could get you would not go to Waitrose or M&S and if you wanted a top quality organic free range bronze turkey you would not go to Aldi or Lidl.
We have an auction house in our town. It sells the ordinary stuff from house clearances and commercial over stocking. When we moved here small items of furniture, rugs, a box of books and a lawn motor sold there, but when we had some silver objects to sell we went to another local auction house that specialised in good brown/antique furniture and pictures. As with you, they sorted through, sold some in the next auction and kept some back for a specialist auction.
The fact that they immediately assessed it and decide it was good enough for a specialist auction, says you are inthe right place.
If you want to sell at auction and haven't done it before. Visit an auction on the viewing day, usually the day before the auction and look at what it being sold. If it is all inexpensive household items and you have a superb silver teaset, then that auction is wrong for you. Visigt another one full og good old and antique furniture, good dinnerset and a cabinet full of beautiful silver ware, then that s the auction for you.
As to doing business with an auction house, they have printed terms and these will explain everything. Essentially they will charge a buyers premium, quoted as a proportion of the selling price - usually between 15-20%, plus VAT.
Rings and other shenanigans are at the centre of programs like Lovejoy and other crime series involving antiques, but in reality they are very few and far between. I've never seen any suggestion of crooked dealing at auction.