Tag with Done Alternative with Date - TaskPaper Applescript

TagWithDoneAlternativeDate.scpt

tell application "TaskPaper"
	set selected_entries to get selected entries
	set theDate to (do shell script "date +'%Y-%m-%d'")
	
	-- Iterate over selection to determine if we are adding or removing done tag
	set add_done to false
	repeat with each in selected_entries
		tell each
			if not (exists tag named "done") then
				set add_done to true
			end if
		end tell
	end repeat
	
	-- Iterate over selection and add or remove done tag as needed
	repeat with each in selected_entries
		tell each
			if add_done and not (exists tag named "done") then
				make tag with properties {name:"done(" & theDate & ")"}
				if exists tag named "today" then
					delete tag named "today"
				end if
			else if not add_done and (exists tag named "done") then
				delete tag named "done"
			end if
		end tell
	end repeat
end tell

Would love to have the function added to SublimeText PlainTasks to add a tag for the project name when marking done.

I tried:
set projectname to project make tag with properties {name:projectname}

but I just get an error:
Can’t make project into type rich text.
-1700

I'm sure someone more talented at Applescript could format the project name correctly?

Note: I tried to incorporate this script but I ended up down the same rabbit hole: http://www.hogbaysoftware.com/wiki/GetProjectTag