Excellent idea for a thread - long overdue.
Perhaps I might start the ball rolling with a few observations relating to F. E. Woodward sliders?
W 8.jpg
The dimensions of Woodward sliders, taken from the forty-odd examples in my collection, all fall within the following parameters:
Length:
38.5mm to
39mm
Width at bend:
5mm to
5.5mm
Width 3mm from bottom end:
4mm
Thickness:
just over 1mm
W 9.jpg
Tapering gently inward from the top end to the bottom, the vast majority have a characteristic crimp close to the bend, though there are examples which bear no crimp whatsoever:
W 1.jpg
Not all Woodward sliders are marked with the company name. Excluding Woodward-made Queen's Royal West Surrey badges, approximately 13% of the badges in my collection are unmarked:
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Given that the Woodward crimp can, on occasion, be recklessly deep, some sliders appear to have been strengthened/repaired at point of manufacture by means of a blob of braze over the crimp itself:
W 3.jpg W 4.jpg
Conversely, some crimp marks can be quite shallow and not nearly as deep as others:
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But by and large, the vast majority of Woodward sliders bear the characteristic crimp and the company name, though the orientation of the Woodward mark is not always consistent:
W 6.jpg
There are also fake Woodward sliders, some of which are seen more frequently than others; one which springs immediately to mind is the Rydal School OTC badge. I have a small archive of images depicting questionable Woodward sliders/badges, which I will endeavour to add/upload in due course.