Easy enough to do the fixie bit, just save the bottom bracket cups, change the crank axle to whatever arms you're planning on using. You'll find it's a nice frame. I assume you've caught all the wonderful things said about Peugeot's on this forum. Well, the Gitane's every bit as good, although it never gets the same credit.
On the good side, that usually means a comparable Gitane sells a bit cheaper than the Peugeot. I remember those Gran Sports were about the best bottom line bikes during the 70's bike boom, even if they did sell for $129, while a Raleigh Record went for $100 and a Gran Prix went for $125.
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Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)