Hi David,
I found this an interesting challenge and gave it a go BUT I can't find one anywhere either. Web searches only led to vendors who no longer sell the MC-4850. There were no listings on eBay.
I don't know if this will help much but I spoke to one of my favorite vendors, Ristenbatt.com, and was advised that Panasonic doesn't have a similar model out now. The man I spoke with at Ristenbatt suggested the Hoover Telios S3332.though not quite the same qualitatively, it might be a close fit your wife might approve of.
Check out the Hoover Telios at -- http://www.hoover.com/product.aspx?model=S3332&ds=false The cost should run around $110 to $120.
Best,
Venson
