No. 8, Sterling or anything else?

[Melanie_Daniels]

I bought this bayonet in a British auction in the 80th:

It was sold as Bayonet No. 8, but it is totally unmarked. My main problem wtih this was that blade and pommel came from an early Sterling bayonet - I think that is the reason I got it cheap. Since then I found another in a private collection. And now two further:
War Department Militaria | Rare No 8 Bayonet
https://www.ima-usa.com/products/ori...39491880255557
The first of the bayonets has a Sterling-marked blade.

In Skennerton`s "British an Commonwealth Bayonets" ist a simillar bayonet with plastic grips (B313 on page 252-253 and 254). But he merely states that it does not fit either the No. 5 rifle or the Sterling SMG.

The Canadian C1 SMG has another bayonet holder then the Sterling, so the C1 rifle bayonet also fits on this Canadian Sterling. Is it possible that Britain made trials with another bayonet (holder) for the Sterling in the 50th?
Or:
I read, that Canada bought 11 British made Sterlings for trials in the 50th with a modified bayonet holder. Is it possible, that these bayonets are made for Canadian trials.
Or:
Any other ideas?