Gretsch Junior Jet_0004_9 Published October 12, 2015 at 900 × 600 in Upgrading a Gretsch Junior Jet. ← Previous Next → The tailpiece too was also upgraded. The original (bottom) had a G-string ridge which compensates for a wound string. Using 10’s however, the G string is unwound – so the new bridge (top) has the appropriately compensated G-string ridge.