Splendid Silent Crusader Shoulders

Or if you have funds for it: old fashioned scrolling: Buy massive amounts, scroll each one with 1 scroll. Those that didn't explode keep and fuse the ones with less slots.

Then buy another round to increase your chances of +1 shoulders, scroll each one with 1 scroll and keep the ones that didn't explode. Fuse the rest.

Once satisfied with adequate of +1s, scroll again. keep all. Attempt another round- if multiple +3s YAY. If not get the old +1s and scroll their last slot.

Potential each one with 70% or 90%

You'll get at least 1 depending on your sample size. 3 lines is a completely different story though.

That's not how fusing works. Fusing creates an entirely new item and thusly resets all scrolling.