I bought my '71 S-100 without a pickguard and initially I didn't miss it. I enjoyed seeing as much of the transparent cherry burst on the woodblock body as possible. At some point @hansmoust advised me that my guitar would originally have had a black pickguard. Recently @GGJaguar and @mavuser kindly brought my attention to someone selling vintage Guild pickguards on Ebay. The seller was a former long term employee of Guild at the Westerly factory. He was kind enough to send a fresh set of screws for the pickguard too which was much appreciated as the old ones were corroded. Anyway the pickguard arrived yesterday and I put it on and to my surprise I really like it. The guitar feels complete now.