Hi Thomas,
Welcome to Rootschat and thank you so much for posting here.
As my grandmother was a WIBUSH by birth I began a one-name study as I believe (and aim to prove one way or another) that there is one origin for the name. I'm fairly certain that the ealry ancestors came from Lincolnshire (I have them there as early as mid 1300s), although as yet I do not connect all branches to one common ancestor.
On your line the latest generation I have is Ambrose S WIMBUSH born c1908 in Missouri; and his siblings Florence, Bertha, Pearl and Mildred.
Through Ambrose Frank (1871 Witney, Oxfordshire) -> John T(homas?) (1845 Tingewick, Buckinghamshire) -> Thomas (1817 Great Bourton, Oxfordshire) -> Benjamin (1789 Bourton, Oxfordshire) -> Thomas (1740 Culworth, Northamptonshire) along with their spouses and siblings.