Just installed the mod, using an existing save game but only see 3 in the upgrade section of the assemblers, inserter, iron chest and electric drill, don't see the Furnaces or the steel chests even though I have unlocked steel processing.

Is there something else I need to research or do ???

Fixed in 0.5.2.
The mod can now be added to existing saves.
Sorry it took so long.

P.S. - [Steel processing] only unlocks the steel chest recipe, in order to get the steel furnace you must research [Advanced material processing].