Indeed. You wouldn't even have to extend it all the way down. You could do a Neo-Crusader kind of thing. That would be cool, and save you from having to completely separate your face plate there.
The real definition of a Mando helmet is that it remains distinctly Mandalorian, so you nee to ensure that the bucket has the T visor in it, I think the suggestion that it is a crusader type bucket sounds about right. It wouldn't stand stead against the modern style (boba) bucket, but there are differing eras to think about and all of the eras have their own specific CRLs, so you are best checking them out on the Mercs Website.