Go here and check out his complete race record. Equibase Company - Thoroughbred Racing Information
Of his 21 race starts, he has won 1 time, placed 2nd 2 times, third 3 times, and earned $3663 in winnings. The last race he ran in was a $2500 claiming race and he came in 5th of 8 and won 88$. (I am not sure how to read the report-- it looks like he was claimed.)
IMO that is not really a successful racing career.
Here is only a moderately successful racing career-- Equibase Company - Thoroughbred Racing Information
32 starts with a 9-8-1 record, and earning $76,404. She raced until 7 and was retired sound to become a broodmare. I only would call her racing career moderately successful because she was not a stakes contender, she only ran fast enough to compete in races with moderate purses, and in her last few races she did run in a few claimers down around $4000. She did have a pretty nice win-place-show ratio to races run.
You could try racing with this gelding, but my opinion is that if he hasn't, at his age, run well enough to win more than one 1 of his 21 races, at the lower levels he is racing at, your odds of him winning enough to even pay for his training and feed are very slim. If he is sound and attractive, re-training him for a career as a hunter, jumper, or other type of riding horse to re-sell would be much better odds for at least breaking even or making a small profit.
Just to clarify-- I don't race horses and its not my "thing" so I am speaking from an outside perspective. I do own the mare whos record I posted-- I bought her as a proven broodmare and am deciding what Appaloosa stallion she will fit best with for producing all-around Appaloosa performers, with a possibility of producing an all-around showhorse that can also be competitive in the speed events at Appaloosa breed shows. (Barrels poles, keyhole, etc.)
When her previous owner decided to sell her, he was not successful in marketing her as a race horse broodmare, and he worked at the track, so that tells you something about how her record was being considered as far as her "success".