Synology NAS and GCP
Just in case it's of any interest: Synology's NAS boxes can act as a Google Cloud Print (and AirPrint) "gateway" for older printers (either network, or connected directly to the Syno).
I can now print to our venerable HP LaserJet 4100TN via GCP or AP, although GCP seems to be a bit hit-and-miss when out of the house (in terms of whether it works or not). I suspect the problem is more likely to be down to the GCP add-on for CUPS on my Linux netbook, than the Syno, but if I ever really need GCP to work for when I'm away, I'll take a good look at the problem...