I know some of the Hart family having worked for Sid Hart Snr. in the Bull Ring, first as a Saturday lad and then afterwards full time whilst waiting for my O level results, which then turned into about 3 years! I went junior school with Paul Hart, who was the same age as myself and with Sid Hart jnr who was about a year older.I have recently been looking at the name Hart as it features in my husband's family. I discovered that it could be a gypsy name and the earliest one I can find (late 1700's) was a horse dealer from Kent. They had moved to Birmingham from Lye in Stourbridge where they lived on Lye Waste (in Mud City) as nail makers and horse nail makers.
Elijah Hart had a daughter Mary born in 1879 and they were living in Gt Brook Street, Duddeston in 1891. Hart was obviously her maiden name. They may have moved to be near to the barracks as I know there were horses there and they continued with their nail making trade.
I've had a quick look for deaths in Birmingham for a Mary Hart and have only come up with two so far - one in 1967 (birth c 1883) and one in 1968 (birth c 1874).