If by 55 links you mean 55 link pairs, i.e., 55 inches, 1/4" is not a lot. Less wear than the 1/16" in 12" (12 link pairs) that most of us use as the time-to-replace indicator. So your cogs and your chainrings should be fine. If, however, you mean 55 half-links (27.5"), then you probably have worn out at least some of the cogs and maybe the chainrings too. The reason I suspect you mean 55 inch-link pairs is that that would be a typical total length for a chain on a bike with a derailer.

I loved Sedis chains too. Even though you only got 30 years out of yours, I hope you will be less disappointed with your new one.