tut, These suggestions come from someone who has taught stockmaking to numerous folks both experienced and first timers.
I would not recommend a fullstock for a first project and I wouldn't much count what you did 25 years ago as experience. That said the Rem. from the Custom Shop is pretty handsome for a Rem!!
Blanks need to be somewhat oversize to achieve good layout, both in width and length. Fullstock blanks need particular focus on forend grain as well the normal considerations. I'd make a plexi template with a forend extension. All Black walnut is porous, English is always prefered. That said long English is expensive. 2 1/4" thick is normal, ends of blank may need trimming for minor checking.

Even the best machined stock leaves lots of work, sometimes better off with less machining if you know what you are doing. Forend bedding is always critical, even more so with fullstock. Must have some sort of muzzle cap with a plan for installation and bedding. Forends are particularly difficult to hold while shaping, movable stand neccisary.
And about 179 more things...
Check out the Ottmar rifle on my website for a truely elegant fullstock!
Best,
Steve