The Watkins side of the family appears to originate from near Talgarth/Brecon, with Levi Watkins senior being born there 1838. Likely 1841 census entry (spelt Leavy) at Cuminbach, Llandefalle (written as parish of Llandefalley South), in Breconshire. Remarkably near the base of my good friends at Bicycle Beano! The photo below (was the banner photo for the website) was taken at Llandefalle church – plenty of Watkins names on gravestones here.
The 1851 census hasn’t yet been spotted, but he married Phoebe Griffiths in Merthyr Tydfil 13 June 1859 and was then living at New Tredegar.
Other Watkins family trees online have origins clustering around Radnorshire and the Marches (Welsh border country into Herefordshire). Many no doubt inter-relate in the mists of time.