John, with John Currie's death pre 1855 might be difficult to find further details for him. Sometimes though you can get some clues by going sideways...
There is a Robert Currie, a peer to John. Could he be a brother? From 1851:
Robert Currie 66 Baron Officer b. Eaglesham
Elizabeth Currie 50
Susan Currie 38
Robert Currie 33
Janet R Currie 16
Hugh Currie 13
Address: Polnoon St 31, Eaglesham
John and wife Ann showed next door at No.30 that year didn't they. John's occupation given then as spirit dealer public house.
If Robert died post 1855, you might get further clues re potential parents to John?
Monica

PS: what is the reference to Watson?