Thanks all for the advice. Having looked at the front brakes they seem to be in far better condition than I imagined with basically brand new pads, decent discs, and what look like refreshed callipers (though probably many years ago). I haven't stripped the rear drums yet but the wheel cylinders also look pretty new from the back and I'll have the drums apart to inspect when I change the hubs to wire wheel ones. All in all the mog is running great and I had my first proper drive of her today - she's everything I wanted and more!
Many thanks again, appreciate the input!