Hi Robert
I would think you are correct about the two names being originally the same. Quite often the spelling is a transcription error but it's always possible a branch of the family decided to spell it differently. !!!!
Perhaps as your research gets back in time you will see when the change occurred, if it did, that is.
I did notice there are also some Yours on the 51 from Wycombe, they could also be part & parcel.

OOps, as posted by Tazzie
Maddie