a picture would be worth a thousand words.....First: is it a MkI or a MkII bayo
? Next: is the blade still it's original shape? (IMHO, at least 97% of the MkII bayos had their blades tapered)- original "breadknife" shaped MkII's are really scarce.
Pricing? Right at the bottom, if the spring-loaded button and the walnut grips are still decent, there's $25-$30 at least. If the scabbard is still complete and decent, at least $35-$40 there. From the top end: a really clean MkI in a good scabbard that would rate say at least 8 on a 10-scale, $200 plus would be realistic. Same for a cut MkII, but for an uncut original MkII, at least double.
The other factor would be CEF markings. QOR, 48th, CE etc. would increase value. Please can we see a photo, and if only one,showing the markings on the left side?