In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
One example: Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lo during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Link Information: Operation Market Garden was a failed World War II military operation fought in the Netherlands from 17 to 25 September 1944. Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin?
Solution is here: from 17 to 25 September 1944
Explanation: The passage describes the 704th's actions during Operation Market Garden, and the answer specifies when the operation happened.

Now, solve this: Passage: Old Black is a 1953 Gibson Les Paul Goldtop, painted black and customized considerably. After the guitar had been left at a guitar repair store, the original P-90 bridge pickup was replaced with a Gretsch Dynasonic single-coil pickup. Eventually, a mini humbucker pickup from a Gibson Firebird guitar replaced the Dynasonic. The neck pickup has always been the original P-90 pickup, but it is now covered by a hand fitted aluminum P-90 cover, replacing the original white plastic cover. The guitar was roughly resprayed to jet black, and received a new Tune-o-matic bridge (not available when the guitar was produced) and a B-7 model Bigsby vibrato tailpiece. It would presumably also have had a white plastic pickguard at some point, as was standard on 1953 Goldtops. Old Black is notable for its metal hardware, including aluminum backing plates. The pick guard is chrome-on-brass/bronze. The tuners have been replaced with Schaller M-6 tuning keys, and the rest of the hardware is mostly nickel-plated. The headstock displays a partially painted-over mother-of-pearl inlay, sometimes referred to as a "wheat stack", rather than the typical silk screened "Les Paul Model" logo, along with single-ply binding around the headstock, although the binding has now fallen off.
Link Information: first sold by the Gibson Guitar Corporation in 1952 Question: How long had Les Paul guitars been made by Gibson?
Solution:
Answer: 68