This video shows the 5 combinable items in the game, including their price if you sell the pieces individually versus the price if you combine them first. Spoiler alert, combine them! Also, i have no idea why my brain said “Silver key”. It’s a ring.
Silver Ring + Azure Eye = Azure Eye Ring
Animal head + Animal body = Wooden Goat
Madalina head + Madalina body = Miss Madalina
Necklace with 2 holes + pigeon blood ruby + large pigeon blood ruby = Dimitrescu Necklace
Mechanical Part (cylinder) + Mechanical Part (shaft) = Heisenberg’s Hammer