Hi Bob ...
My apologies for the delay in getting back to you.
I have now had a chance to check through my SYRETT paperwork, but unfortunately I have nothing further on Shadrach and his family.
However, on re-checking those IGI entries mentioned in my original posting on the new format Family Search I found two further children born to the couple - one unnamed in 1787 and Ann in 1795. These two - plus Charlotte (from my original posting) in 1789 - all appear in the Non-Conformist Record Indexes. Perhaps this is where you need to look for Shadrach and Ann's marriage (rather than parish registers)?
Sorry I couldn't be of more help.
Penny