Most slide bracelets are based on Victorian Era styles. During the later 1800s and into the early 1900s, a lady commonly wore a pocket watch on a chain around her neck with a decorative slide that enabled her to adjust the watch to a particular length. In the 1930s collectors started putting these decorative slides on double strand gold chain bracelets. Eventually they would collect slides enough to complete a full bracelet.
During the 1950s Victoriana briefly made an encore appearance and reproduction slide bracelets, usually in 14K yellow gold, were all the rage. So even though they are reproduction pieces, slide bracelets from the Fifties are still considered antique and worth more than their weight in gold.
Look at the two examples below of reproduction slide bracelets. The gold is still quite shiny... the charms are mostly 14K yellow gold. You'll find that with authentic Victorian pieces, there are A LOT of slides that are not actually gold. So there is a plus side to later pieces modeled after the Victorian designs. They can actually be worth more.