Hi Falcon55/Jack!
Nice having you on the forum and sharing your treasures with us. Some really pretty salt cellars.
It isn't unusual to see older pieces with new glass liners in them. The glass pieces are easily broken over time and then the search is on to find a "newer/modern" replacement to fit the item properly.
It is really hard to tell when your piece is made since there isn't an exact silver hallmark to help identify the maker. But, due to the style and decoration as well as the actual piece itself (salt shakers became more popular in early/mid 1900's and disposable containers with pouring spouts)....I would venture that your piece CAN RANGE anywhere from late 1800's to early 1900's.
Can you please post a picture of what you describe as the "original" liner. That could help in determining! Thanks!
ALSO, if you ever find some silver TRENCHER SALTS....they are worth more and some are amazing in the values they demand! Here's an example of one below. They are a "trench" in a base/pedestal. This one is on display at the Metropolitan Museum of Art but you can just search and see beautiful examples.