The Georgian House (mentioned on p. 58 of the RS Ireland 2017 book) is closed. We got off the HOHO bus at Merrion Park in order to visit this, only to discover that it is closed for improvement looks like it won't open again this year. We took the opportunity to stroll around the streets taking photos of the beautiful Georgian doors, and then found our way to Grafton St., so it wasn't a loss of good touring time.
I'm not sure if this has been updated elsewhere on the RS site, but wanted to make future Dublin visitors aware.