A friend has a favorite canvas back pack that has a zipper that does not work ....... wants to get it fixed rather than buy a new back pack ........ I recall once noticing a sign for a LUGGAGE REPAIR shop somewhere on the east side of Sukhumvit which might be a solution for him ...... does any poster here recall the exact place for the LUGGAGE REPAIR shop ...... or another place that might be able to repair or replace a long, heavy-duty zipper? Thanks.