Shieldaig, named after a lovely seaside town in the western islands I believe, is an independent bottler of multiple distilleries' whisky product. That means they visit, taste and buy special casks or overages of various distilleries and may then age tehm further before bottling them under their own label but also with the original distillery's name. I can only assume that this is an independent bottling of Speyside distillery's whisky by the Shiedaig folks. Maxwell must own Shieldaig, although my research has not born that out or refuted it.

Some other Shieldaig bottlings:

http://www.whiskybase.com/bottlers.php?bottlerid=75