Welcome to the forum, Roger
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You are right in saying that famous master names are often used to value up swords made by common smiths ... or even pure fakes.
Sebastian Hernandez was the name for both father and son. We can see their personal marks in the Toledo Palomares nomina (chart). You may check if their marks are shown in the blade ricasso (behind the guard). It could be that this hilt doesn't have a Toledan origin, judging by its style. But don't rely in my humble judgement. Let us just wait for members more within this typology.
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