Weighted or not?

Hi Everyone,
I believe if a sterling item, say, for example, a cup or cordial, is covered on the underside, it usually means it’s weighted silver. Sometimes it mentions it’s weighted and sometimes it does not. Often, when something is weighted sterling, even the part that’s not the base is very thin gauge silver. I present a three inch tall cordial from a set of six with no maker’s mark but which is engraved sterling 950 on the underside; it has a different type of underside covering than those I usually encounter. The rest of the cordial seems to be of fairly good thickness.
Has anyone encountered this type of underside covering regarding where the item is not weighted? Neither feeling the heft for balance hints, nor tapping the underside led me to conclude one way or the other. Maybe I’m just not experienced enough to make a determination based on those factors. Would I need to drill a hole in the bottom to find the answer?
Thanks,
DougL