Thanks Annie, Phil and Ady,
Commonwealth/USA - Hmm, good point, I haven't. I have picked up, via a CWGC search, someone who'd been born in Winscombe but had emigrated to Australia - He'd been on neither memorial at St James, or others around the village.
Parish [parocial and secular records] have been trawled though; the're sketchy enough to believe something is still out there : for example no correspondance seems to remain on how the names were 'selected'.
Migrant workers are a distinct possibility [Railway, mining and agriculture]. One of the reasons I've found for being on the tryptych but not the cross was a very strong lineal connection to the local gentry but not resident/born in Winscombe/Sandford so possibly lack of local roots accounts for FT's absence from the cross.
Local private school [Sidcot] has been trawled - changed my "received wisdom" on Quaker involvement as their losses (including 'in action') are about double the village. This is where the "religion" factor comes in: One of the men of the tryptych but not the cross, was an ex-Sidcot pupil who'd married a local girl. Despite his parents getting permission to errect a plaque in St James within weeks of him dying, he still didn't 'qualify' for the cross - There is a possibility that FT's non-conformist/methodist though brief searches there reveal nothing..... [for a small village, we've got a good choice of worship!]
I'm almost sure the guy's dead [i mean, "in period" - he's specifically identified in two records!] BUT it is a distinct possibility he's not strictly a war casualty - one of the other men mentioned on the tryptych but not cross, died of an infection in 1919 - his service record [luckily in TNA] mentions no injury and he's not in CWGC records.
I've checked the absent voters which hasn't given any info on this case BUT did on another person who's named on the tryptych but not on the cross - that person, well the Winscombe version, seems to have been very much "alive" perhaps even into the 40's!] BUT shared his name, initials and rank with someone else who did die! It could be that there was some confusion when the cross was put into its current layout!
So there we have it....perhaps the '11 release will provide the 'magic bullet'!
Thanks to all...still receptive to any ideas on my possibly non-CofE, possibly migrant, possibly not 'dead' WW1 'casualty'!