Hi,
In 1841, Hill Street, C-o-M there was a Robert Alley, 25, a Carter by occupation. With him are his wife, Anne or Annie, also 25 and William aged 2. I know it isn't Alty but spelling was pretty erratic then. Let me know if they look likely.
There isn't a house number unfortunately, just "Hill St." at the top of three pages and "Do" under all other entries on the pages.
I looked on the 1841 because I have it spread out in front of me when I saw your request. I will now dig out the 1851 for you. Will post a message when I have taken a peek.
Bye for now, Doreen