Carpetsahib,
Nice work - where did you get the walnut blank for the completed No 4?

I've got a pre-98 Lee Metford that's already been bubba'd, that I'll turn into a faux Lee Speed after I get home. For you guys building your own, I picked up one of these from SARCO

MSR219 MK10 MSR 1 Fixed 2 Folding Leaf Express Sight (round bottom) 3/$138.95 $49.95

MSR221 MK10 MSR 3 Folding Leaf Express Sight (round bottom) 3/$138.95 $49.95
http://www.sarcoinc.com/mauser.html

For what it's worth, I also have a .303 BSA 'Cape Rifle' - this has a 30' barrel, same length as the Lee Metford service rifles. While mentioned in period catalogs, so far I've seen exactly two others like this (for sale in the UK at http://www.wdlr.org.uk/stensby/firearms.htm) with a barrel rib.