I semi- destroyed a very nice JCM800 Marhsall Cabinet following some bad advice about installing casters- i took it as gospel truth and almost ruined my cabinet.
Okay, so I dismantled the bottom half of the Cabinet, and oredered a Baltic Birch ( similar to Marshall woods) piece of 24X 30 Plywood from " ROCKLER". Total cost shipped was less than 25 dollars.
I hope to repair my Marshall JCM800 and in the futrure always trust my instincts first, no matter what "expert" gives the advice.
Rockler delivered the goods, but ,damn, was it pricey for that small board!;
http://www.rockler.com/product.cfm?page=846