I know nothing about restoring old machines but I know a thing or two about dusting my furniture. To me, the completely uninitiated, it looks like a gentle wipe with a damp cloth would reveal those stunningly preserved decals. If I had come across a machine as beautiful as this I would grab it in a heartbeat. Wouldn't matter to me if it ever sewed another stitch. It would simply be in a place where I could see it, and smile at it's beauty, every day. Please do share a picture of her after she's been cleaned up.