WW2 Fire Guard Keighley Area Marking Badge - Or Is It?

Have to admit I'm a bit on the fence with this badge. It was claimed to be a WW2-vintage Fire Guard badge for Keighley on eBay. ​Measurements were 6.8 cm x 4.5 cm. It certainly generated a lot of interest and late bids took its hammer price to £91 (plus shipping).

It does have the look of a WW2 badge but a couple of items had me a little confused. Firstly, the use of a red thread is very peculiar on the backing. It seems odd (and a waste) to use such as colour on a bobbin thread. Hessian can be used as a backing but this is a tad coarse for the purpose. From the measurements given I assume it was intended for placement on the battledress pocket like the CD badge.

It may well be genuine and needs further research, and if the real deal it's a very rare survivor. Clearly a couple of bidders were in no doubt about the badge's veracity.

WW2 Fire Guard Keighley Area Marking Badge