I'm guessing you're talking about a Winchester 1892 or clone?
The only levergun stocks I've ever seen are for Win 94s and Marlin 336s. There aren't too many people interested in restocking lever rifles in the first place,and probably fewer who want to synthetic restock rifles that are either antiques or used mainly in cowboy action where a traditonal wood stock is going to be the norm.
It's sort of like insisting on a polished walnut stock for your brand new FN P90.
Why not just get a new walnut stock?
My first recommendations would be gunparts corporation (Numrich Arms), Brownells and Midway for finding a new stock.
If you had to restock it with a synthetic, try a Ramline Win 94 stock injection molded stock. You could possibly inlet that to fit a 92.