Hi Ray. I guess it depends on what you mean by Mantel Clocks. Are you talking the highly detailed Victorian style mantle clocks? Or are you talking the smaller desktop clocks that takes the small clock inserts?
I'm also assuming you're interested in selling the clocks themselves and not the patterns.
I think you're more likely to sell the small desktop clocks with the clock inserts (like this one). Those type of clocks appeal to people who are looking for gifts. I'd focus on clocks that cater to an interest. Dog breeds are always popular, cats, golf, sports, cars, motorcycles, and hobbies. Also, sports silhouettes with a jersey number next to it will be popular with proud parents.
For generic ones, I'd have one or two (or more) available. For specific/custom ones like dog breeds or sports w/ jersey number, I'd make a sample and take custom orders. I wouldn't count on cutting anything while there. You'll be too busy talking to customers.
If you like more detailed mantle clocks, I'd do a few. You might sell one every once in awhile, but more often than not, they make great eye candy to bring the customer in the booth. Once there, they're more likely to purchase a smaller, cheaper clock.
If you don't have it already, I'd recommendMiniature Wooden Clocks For The Scroll Saw.
Variety is the spice of life. I'd have lots of things for folks to look at. Make sure they know you take custom orders too.