The book we have lists S-7 and H-13, 4140 is not listed. We use S-7 almost exclusively and normally draw back to a much higher Rockwell than you are talking about. Our book lists the following for S-7:
S-7 - Preheat 1200-1300F, Heat Treat 1700-1750 @ 1/2 hr per inch, Draw at 1100 for 48.5 Rockwell C. We usually draw at 525 for our injection molds leaving us with a Rockwell of about 54.
H-13 -Preheat at 1400-1500 until soaked completely. Heat treating at 1750 will yield approx. 48.5 Rockwell, they suggest min. time of 30 minutes for first inch and 20 minutes for each additional inch in max thickness. The draw temps you list for your H-13 appear to be real close. On the chart they show you are working at the high end of the temperature range the hardness drops from a high at 1100 of 52-54 down to 42 at 1200.
Hope this helps.