Ossie Harris had a losing record, but I reckon he could fight some, and I don't think he missed too many of the top guys of his time. Check out the competition he faced in his first 20-25 fights. http://boxrec.com/en/boxer/9979
Harris had one very hard road. However, I always thought Jimmy Ellis was really thrown in at the deep end of the pool. In his first 20 fights he fought Hurricane Carter, Henry Hank, Don Fullmer, Georgie Benton, Rory Calhoun, Holly Mims (twice), Wilfie Greaves and Johnny Morris. Wow!
Jimmy Britt fought Lavigne and Erne is his third and fourth fights, but they were on the slide and he was a champion amateur. He won both by KO. Very underrated IMO.
I knew Wilf Greaves briefly and had I the sense or interest at the time I could have gleaned a lot of insight from him, a very good box/fighter, tough & capable, he also looked a bit like a sawn off Chuvalo.
Ezzard Charles had some very hard opposition early on, like an experienced Charley Burley at Middleweight.
I never thought that much about Ellis' early career ,now I've looked at it,he was indeed," swimming with sharks," very early in his career.Mimms x2 Calhoun,Greaves,Hank in his first 13 fights and Carter after 17 bouts,stiff competition !
David Reid was moved pretty damn fast. He'd fought Simon Brown, James Coker, Laurent Bououani and Felix Trinindad in his first 14 fights. Pretty reckless match making but as we know now he was pretty much damaged goods with his eye issues when he turned pro.
A fighter oft-overlooked is Ruben Navarro. This guy was so hot on the west coast it wasn't funny. Of course he was in tabloids as much as he was in the boxing mags at the time, which probably helped making him a box-office attraction. Anyways, in the beginning of '68 after 11 pro fights they throw him in with Pete Gonzalez (ranked #7 jr. light at the end of '68), then Ray Adigun (ranked #9 lightweight at the end of '67), then world 130 lb. champ Hiroshi Kobayashi in a non-title 10 (which he won), then Arturo Lomeli (#5 jr. light at the end of '68), then former and future champ Yoshiaki Numata. And with a record of 15-1-1 they match him for the vacant jr. lightweight title against Rene Barrientos over 15 rounds. This was all within his first 2 years as a pro. No record padding with soft touches there.
Lightweight Bobby Woods of Spokane was thrown to the wolves like no other fighter in history. Started as a pro at 15. Fought Willie Pep, Harold Dade (twice), and Jackie Blair (twice) when he was 17. Jackie Blair (twice), Cisco Andrade, Fabela Chavez, and Joey Velez when he was 18. Joey Lopes, Henry Davis (twice), Ralph Dupas, Carlos Chavez, Lulu Perez, and Sandy Saddler when he was 19. Jimmy Carter, Carlos Chavez (twice), Jimmy Savala, Joey Lopes, and Vince Bonomo when he was 20. Had five fights when he was 21 after which he was diagnosed with a detached retina and brain damage and disbarred by the Washington State Boxing Commission. His record was 51-29-8. Underlined fighters were world champions. Henry Davis was at one time No. 1 contender. You can look up the rest, but I know that Andrade, Carlos Chavez, Joey Lopes, Lulu Perez, Jackie Blair were longtime rated boxers. Many of his other opponents were also top-notchers.
Everyone knew about his eye issues at the time. I remember watching his very first pro fight on television and the problems were discussed then and were, of course, obvious when you looked at him.