When I'm typing TiN I'm talking about Titanium (Ti) Nitride (N), and TiAlN is titanium aluminum nitride. This I'd not an electroplating process. This is a PVD - Physical Vapor Deposition - coating process. It has nothing to do with the element Tin.
The TiN is the same as the gold colored coating that you often see on drill bits. TiAlN is a similar coating that is composed of a combination of titanium and aluminum nitrides.
The top ring/cap and the air control ring are TiN coated, the dark colored parts are TiAlN coated.
This isnt the sort of coating a local shop is likely to do unless you are located in a major industrial area like Chicago, new york, Los Angeles, Seattle, etc.. There are only 3 locations in Canada that have the technology to do this and they're all in the Toronto area.