"Note that this in actuality also restores a third item - as buying either of those two items from Vrischika also makes a new tattoo available from Fell (what doesn't?)."
does that mean this new tattoo from Fell is effectively of zero significance? is it a specific tattoo that has no equivalent or other source, or are 'new tattoos available from Fell' added to its catalogue randomly from a list by these apparently plentiful 'triggers'?
no, i have not yet finished a playthrough of PS:T if that weren't already screamingly obvious. 
only asking because i have no interest in the cheat items themselves... unless i ever reach the point of sheer boredom (which, considering i have barely even begun to explore Sigil in depth over the past decade, could take a mighty long time) + money to burn ... or this tattoo (if distinct) is for some reason appealing enough to 'unlock'.
