Many thanks for your clear ID confirmation comments, Jeff.  And nice additional photo!!
Chris

Hello Chris,
Perhaps you’re considering the possibility of Hume’s Warbler – once considered a southern sub-species of Yellow-browed, but now a full species. Both have a post-breeding moult in early spring and before this, in winter, can look much drabber due to feather wear than they did as fresh 1stW birds in autumn. Have a look at my photo, on the link below, and note the ragged worn tail end – a sign of this wear; although only showing one obvious wing-bar it does have very well-marked tertials which on a Hume’s would be well faded at this time. Also its bare-parts colouration supports Yellow-browed rather than Hume’s, although I never heard it call, but others have.
A good reference is The Helm Guide to Bird Identification (An In-depth Look at Confusing Species) by Vinicombe et al.

My photo is on this link https://pbs.twimg.com/media/C1gP-v0XcAEhLOh.jpg

Yellow-browed Warbler still at Hankridge LNR this morning (830am), showing well.

(This is a lifer for me, and I’m relying on others’ ID.  So, many thanks for the postings!)

Despite scoping the bird, it really appeared to have either no or a very unobtrusive second wing-bar.  Is that typical?  Has anyone heard it call?

3-Jan-2017
The YBW found recently by Brian Hill at Hankridge LNR (behind B&Q) at Hankridge Retail Park near Taunton, was still present this morning, favouring a large bramble patch and adjacent small trees in the reserve, just inside the roadside tree-cover between Sainsburys delivery yard and B&Q.

My photo of it can be seen at this link https://pbs.twimg.com/media/C1RJIA3XcAAyA5Q.jpg