I have had the opportunity on several occasions to remove the style of hilt shown in the original photos to make repairs. On every one of these the tang extended completely through the hilt before being peened. I have yet to see a single hilt of this exact style that had a hidden tang combined with a butt plate held in place with a separate fastener. There was one occasion though where I found that the tang had rusted completely through and the hilt was being held in place by a combination of rust buildup on the tang and shrinkage of the hilt material.
Best,
Robert