My best thought is variation 7-a.1, which is listed as 46 x 36mm. With all Soviet variations, it is the little details to watch for:
a. inset pearl just below the flag on the left side; b. the upper flag edge is rippled; c. the defined double loop curls of the rope on the right side of the banner; d. the position of the two tassels; e. there is a pearl immediately to the left of the left hand tassel; f. the pearl below the tassel extends into the white enamel and is not attached to the leaf; g. the shape of the banner pole 'snake' ribbon above the star, at the right edge of the star, and bottom of the pole; h. pearls are defined within the curl of the scroll loops; i. the pearl on the bottom right side is inset and a leaf projects down and to the right from it.
I am not an expert by any stretch but hopefully this gives a few items to watch for. I cannot say where these were made and I have yet to find a source that gives information on the factories producing Guards badges. However, yours is definitely from the Great Patriotic War, a very nice variation and likely worn with pride!