I cut off my examination of runs scored per times on base at 1920 because of the many ways in which the early game was different. But let's complete the picture with guys who reached base 3500 or more times and were active before 1920 (I went through the end of their careers this time, so the numbers for Babe Ruth are a little different here; Frankie Frisch's totals are different but the percentages are the same). The #1 man here, of the 24 guys who qualified, sure does stick out. I ran the numbers both with and without including homers, and ranked by the latter:

Just out of curiosity, I ran the same numbers over the whole 1871-2011 period for three groups of players with over 2000 plate appearances who seemed likely to score a lot: players who scored at least 60% of their times on base overall, players who scored at least 0.85 runs per game, and players who stole at least 30% as many bases as times on base. It will not surprise you that this list is dominated by guys from the game's very earliest days; Keeler sticks out a lot less on this list, when compared to contemporaries and teammates like Hamilton, Delahanty, McGraw, Thompson, Duffy and Brouthers. It's sort of disappointing that the all-time leader here is the obscure Ned Cuthbert, who retired in 1884 with a career .276 OBP, but the #2 man is the game's very first dominant superstar, and the #3 man one of the founding fathers of organized professional baseball:

So yes, while the modern leader over a career with 3500 or more times on base is Kenny Lofton, both Vince Coleman and Miguel Dilone scored more frequently once on base.

PS - Take another look at that list and consider how many guys above 50% batted in front of Cap Anson - I don't know where Anson hit in the batting order in the 1870s (by the 1880s, before you had to announce lineups before the game, he was inserting himself whenever there were men on base) - Barnes, McVey, Dalrymple, Kelly, Gore and Sunday all come to mind.