Paul, especially with the S410, make sure that your front swivel mount is going into enough 'meat' to be strong enough. I took mine partially into the Schnabel at the front (though still underneath the stock), as I prefer a forward-mounted front swivel. A friend of mine didn't, and his swivel didn't end up with enough wood to hold itself. Messy! I'd send you a photo of mine, but unfortunately I'm too tight to buy a digital camera!
Also, to help prevent unwanted undoing of the swivel, and to achieve a much more professional finish; prior to drilling your tapping hole, create a round flat area with a spur-tipped wood drill, of sufficient diameter to accomodate the round body of the swivel when it would be fully screwed home (a couple of quid from Focus/B&Q). This needs only to be deep enough to eliminate the curvature of your stock, and I actually did mine by hand, as it takes so little drilling. This will also give you a nice centre to drill through with your tapping drill (i.e. a drill bit SMALLER than that of the self-cutting thread on your swivel).
Good luck, and don't be put off by the above as it really is very simple!
Chris