the spacing of the rear hub won't have any effect on the chainline. chainline is all about three things -- hub body, cog, and dish. on a track wheel, which is generally symmetrical, you shouldn't have to worry about any sort of dishing. people here have claimed that paul hubs have a 46mm chainline, but i tend not to believe one or two anecdotal lines that i've heard on this forum. i think that paul hubs have a standard track chainline. plenty of people use paul hubs with standard track crank and bottom bracket combinations, which yield a chainline between 42.5-43.5 when a cog is slapped on. it might be worth measuring the chainline in the rear to confirm this. this is all to say that the stronglight track crank and bottom bracket combination should be fine.