Maybe you've already found this info but just in case:
1930 CT Hartford Co West Hartford Heslin Charles T head 39 married at 35 CT CT CT Heslin Eleanor K wife 33 married at 29 CT IRE CT Heslin Robert F son 3 1/12 CT CT CT
I found what I believe are the parents of Charles but I didn't find a sister, Ruth, but a sister Loretta so I'm not sure if this is the correct family.
To order SS applications from the SS Death index go to rootsweb.com and enter name Charles Heslin in the SS Death index section and 6 should come up. Check and see if one of them is the correct one with the correct SS# and if so on the right click on the SS5 letter. This will bring up a form letter which you can print off. If none of them are correct still print off one of the SS5 letters and white out the incorrect name and number and fill in with your info and send in the letter with money and it takes about 6 wks to come back. This app should list his parents' names and then we can search the census again for you. Let me know if you have any questions.