Earthenware Vase J S or T S initials - John Shelly? I.D. help appreciated.

Another mystery vase I bought years ago. I have already checked my studio pottery marks book and bispm.  I wonder if kind experts would take a look and advise. The closest I could find was John Shelly but I think a little different. many thanks

I've got a jug with a very similar mark  impressed in a circle just under the handle.  It's in red earthenware, neatly thrown with a rather Winchcombe-ish wave pattern.  Sorry I can't find it now to give a photo of the base, but it's flat (no footrim) and wiped clean rather than having wire marks.  

I’m afraid I haven’t been able to find it. John Shelly was my first thought too, but not one of his recorded marks, and it might be ST or TS rather than JS

Thanks for comments and photographs. Much appreciated. Many years ago I had a lamp base with a similar mark. I thought then it was John Shelly because of its style and influence. It has long gone so I think I will just enjoy this vase a little longer, kind regards and many thanks