Monarchs and Sterlings are very tough to find, especially in playing condition. You'd be much better off with a modern hand-made. Call all the builders and you'll find one at a fair price.
Might I suggest a handmade from Texas? Anyone? Bon Temps? Poullard? Bueller?
...and other great boxes made in Louisiana, too! Heritage... and...
......................................................................... Le Capitaine by Danny Dyson of Big Lake, Louisiana!!!
My understanding is there is at least a one year wait for Poullard, LeCapitaine, and Bon Temps. I know Danny Dyson (LeCapitaine) is completely full for this year.