Vintage PYREX #404 4L Primary Yellow Mixing Nesting Bowl RARE SUNSHINE BACKSTAMP

RARE SUNSHINE BACKSTAMP - Excellent vintage condition PYREX yellow primary color nesting bowl #404, 4L. See photos for all condition details. There are pics of all around the bowl - it looks like the same picture over and over again lol. When held up to light there are some “flea bites” but the bowl is beautiful otherwise. They do not show when bowl is on display. It is still so vibrant for possibly being over 75 years old! (Made between 1949-1959) It presents more matte than shiny. The inside has little wear. There is one fine line from the time of production (see photos). I will give it one more thorough shining with Peek Polish before shipping! What makes this bowl RARE: On some pieces, apparently confined to round mixing bowls, refrigerator dishes and hostess casseroles, are seen what has been nicknamed "sunshine" backstamps. Encircling the trademark is a ring made up of what appear to be the capital letters "T" and sometimes "I", or both. The significance is unclear, but since it is also seen on the red #404 singles offered only 1949 to 1959, it would seem to be within that time frame. Again, this is a used vintage piece, sold as is.