The difference in original and reproduction goblets in
SHELL & TASSLE aka Duncan #155 is the hardest to discern of all pattern
reproductions for even the most advanced EAPG collector.
Thanks to Sean George, we finally have some actual discernable design differences.

Difference #1 Reproductions may or may not but originals in this pattern
WILL glow yellow-green under a black light in a dark room.

Difference #2 Reproductions are thicker, heavier and usually have a
slight greenish or yellowish hue.

Difference #3 The thin band at the top of the design (all around the shell motif)
is stippled - just tee-nincy dots on the original. But on the reproduction,
those dots appear to be encircled by little 'doughnuts'.

Difference #4 Although both originals and reproductions have veins visible
                 in the shell motif, the veins in reproduction shells appear more
                    like defined lines, rather than the heavy stippled lines in the originals.

This difference is not as obvious to us.

Here's what you really need to know -
but you need really good eyes to see it!
See the little 'doughnuts' around the dots in the top
of the design area?
And here's the top edge of the design portion of an original!!!
See? No doughnuts!

Thanks Sean!!!!

See also
WESTWARD HO! aka Pioneer
U. S. COIN aka Silver Age