I came across this:

[Flying10uk]

Mike, did you find your Belgium made pig sticker mixed in with other British/Canadian/U.S. made pig stickers and you just happened to notice it or was it advertised as being Belgium made? Should the Belgium made scabbards also have the Bg marking or were they identified by another marking?

[Time Bandit]

Mike, did you find your Belgium made pig sticker mixed in with other British/Canadian/U.S. made pig stickers and you just happened to notice it or was it advertised as being Belgium made? Should the Belgium made scabbards also have the Bg marking or were they identified by another marking?

I found it at a local auction a few years back, it was described as a Belgium made one in the catalogue. I paid £30 for it which at the time (2014) was expensive for a No.4 spike but I figured it was going to be my only chance of getting one so it was worth it, never seen one for sale since so it was the right choice.
The scabbards are also Bg marked and have a matching serial number to the bayonet. Mine is missing the matching scabbard unfortunately and came with a std UK type MK1 scabbard.