FWIW I have the LV cast scratch stock (Preston). When I got it I had never in my life touched a beading tool. I had a project that needed a bead so I went and bought it as the price was right. I was concerned about the curved fence, but honestly, the thing is downright idiot proof and I cut a beautiful long straight bead on my first attempt not really knowing what I was doing. In fact, I’ve never ever failed to have it cut dead straight and perfect on a straight board. It works equally well going forwards and backwards. Once I get my line established I can go rapid fire both directions in an absolute blur – probably fast enough to start a fire – then just work the very ends using the body as a depth stop. I gather the LN66 is uni-directionsal??
I will say though – making your own cutters is the least fun I’ve ever had. So last Xmas I asked for the master set so I will only have to make the occasional specialty one in the future.