I moved my rear-mounted saddle lock no problem about half an inch to the right IIRC to clear the Newall DRO on my S7. I made up a little jig to ensure that the drilled hole went through vertically and in the same position relative to the bed. I have a Kipp handle there as a tool-free lock (rather than the hex head Myford supply.) Somebody advertises them on eBay. Occasionally it does foul the tailstock, but it's not too difficult to rremove it temporarily.
The front-mounted lock does have its attraction, but I don't think the Kipp type handle would fit without fouling things so you'd need the spanner to hand or the low-height lock as in the photo above..
Edited By Nigel Bennett on 12/03/2012 12:59:08