I pick up my Mossy 590A1 in a week and have a question...

At Cheaper Than Dirt (http://www.cheaperthandirt.com/48711-57564-1887.html) I saw an adapter that slipped onto an AR bayonet lug that added two Picatinny rails. Has anyone tried to put this item onto a Mossy 590A1 bayonet lug? My thinking is that the are both the same lug that fits current US Army bayonet.
Seems a cheap (well, cheaper than other alternatives I've seen) and sturdy way to add that light I want. Thoughts anyone?

Thanks in advance...