A tad embarrassing this question - but if you don't air your ignorance, you never find out - so here goes. I picked this up at a fair yesterday, and I can't see an obvious way to remove it from it's case. It looks to me like its a front loader, but can't see any obvious release mechanism - the dust cover has the usual blued metal slide, and I'd usually expect this just to slip off so I can access the movement. The thing is - the dust cover won't come off and I don't want to force it - any suggestions ??