I have done several over the years although I have no pictures of the full beaded style only some that are partially beaded ones.
Dependent on the size beads used, the amount of beadwork done, the style of beadwork (lane stitch or appliqué stitch) it can take anywhere from 40-200 hours or so for total construction. Beading is VERY labor intensive.
here's a couple I've done in the last 3 years:
This first one took about 70 hours all together - the beading probably about 60 hours
this one took a bit longer - about 125 hours overall and the beading about 110 hours:
Both of these used the larger, early 8/0 pound beads (approximate size 3/32-1/8")which cover area bit faster than the smaller bead seads, which range in size from 10/0 (about 1/16") to 20/0 (VERY tiny) such as used on the Duke's rifle case which is an original from the late 1800's - most of the cases from that period use 12-16/0 beads.
This site
http://www.nativetech.org/glasbead/glasbead.html
offers the basics and describes the different methods
so yes such beadwork can take as long or even longer than building a rifle dependent on the various factors.
While I'm not the fastest bead worker in the world after 50 years of doing it I'm somewhere above the middle.