I love the old lines and the Swearngin genetics.  They really know how to put together the lines.  I tried 8-10 yrs ago to follow the modern stuff.  The biggest difference IMO is the old lines, matings were more prescribed.  Today's genetics is all about the bull.  Small BW and Large WW.  Curvebender.  Sleep all night heifer bull. Etc, Etc.   Meanwhile 2 years later your high powered bull weighs 200 lbs more than he did at 12 months but large frame and narrow.  

if you are striving for the F1 cross with those shorts- I'd definitely be dipping into those old pure lines.  Most of today's modern genetics are crossed 2-4 times and your vigor is gone.  Just my humble opinion.