Very nice, I agree, nearly impossible to upgrade.
There are a few others nearby this rifle, probably know about them, or in the book, but if not:
1940 243 4029 a N23767 k (laminate stock,pretty nice, but probably not this nice)
1940 243 7436 d N27418 k (laminate stock,stock pretty miserable, an elite restore job)
1940 243 8289 d N28039 k (laminate stock, pretty nice, but probably not this nice)
1940 243 9573 d N27969 k (laminate stock, pretty nice, but not this nice)
1940 243 1278 g N29518 k (laminate stock, pretty nice, but not this nice)
1940 243 5595 i N32257 k (laminate stock, sanded/cleaned, pretty decent overall, bolt match)
1940 243 8909 i N31504 k (laminate stock, pretty decent overall but nearly this grade-metal cleaned harsh, bolt match)
1940 243 6166 n N33774 k (laminate stock, sanded, pretty decent overall, but bolt mismatcher)
1940 243 1683 o N33739 k (laminate stock, pretty good, rougher though, CB's old rifle)
More, but these were easy to lift, some later production lack the unit, only "N" and property marked. Probably all in the book, but I generally do not do "great rifle" posts and this one deserved such, so the extra commentary.