Wait what is the sniper rifle silenced???Only "Iconic" weapons/clothes can jump up tiers, normally crafted clothes/weapons can not jump up tier. Also when you uptier the Iconic item you can only do so once per level and the crafting menu shows you that you need the previous level item before it will let you "jump up". Here's the visual difference -
Crafting a Normal Weapon
Uptiering an Iconic Weapon
See how the "jumping up tier" Iconic weapon shows you that need the previous version before allowing you to craft (which you can only do once) vs the normal weapon which allows you to craft many versions but they can't be uptiered. This is how you can take Panam's uber silenced massive sniper rifle to Legendary from the rare state you originally get it in, with huge performance improvements as you jump up through each tier.
I've even taken all of Silverhands clothes which you get a rare items and uptiered them all to Legendary. Jowever for those particular items its just not worth it TBH, you can only do this once so you get whatever mod slots the game gives you and thats it, no disassembling, no re-crafting allowed.
The one i got im sure isn't silenced so i ended up buying a legendary one from a vendor but there was no silencer mod for it.