Welcome to Watchuseek. I am afraid that we don't give valuations here but your watch should certainly be "above average". The exact value will depend partly on who exactly the maker was since Tiffany never made watches, they had them made for them. The style of the movement suggests Jules Jürgensen but there were other makers who used this sort of bridge layout too. 1883 sound about right with respect to age (presumably determined by the case hallmarks) - a pity that the expert couldn't identify the maker too.
Hartmut Richter
Hartmut Richter