It appeared simply as "縮尺：≒1/82" and the meaning is quite clear (="approximately 1/82 scale").
Jim Breen's wwwjdic does not seem to contain an entry for the symbol.
jisho.org suggests only おおよそ 《大凡》but not the symbol itself.
Just randomly googling the symbol does not give me an answer in which I could have confidence. At least it's listed here, though without pronunciation:
I came across it here, if the source is relevant (one needs to download the pdf for the Hayabusa (隼) to see it in the header.