Are there two types of Spring Blossom Green Refrigerator Dishes?

Oddly enough, yes.  For 1977 & 1978, the final years of production, the design on this particular set was altered in a very subtle way.  The changes become apparent with a side-by-side comparison with the original design which was available from 1972 to 1976.  This pattern update is unrelated to the more obvious 1979 update for the 300/440 nesting bowl sets and 470/480 round casseroles.

When comparing the two versions piece by piece, the floral designs have an overall size difference.  The New version has smaller flowers which are closer together.  This pattern size difference reinforces the idea that there are just 2 distinct sets, and genuine sets at the time were very unlikely to be a mix and match between the two versions. 

The Original 502, with only two white flowers placed close together, had an asymmetric appearance, while the New 502 has an even distribution of solid white flowers.  To give an opinion, the changes apparent on all pieces with the New design have the feel of being refinements, with the purpose of giving more balance and finesse to the pattern. 
 

Above: The Original version is pictured in this 1976 catalogue image.  The design on the 502 is not visible here, it is pictured below in the third photo.
 

Above: 1977 catalogue image depicting the New version. 

 
Right: 501 & 502 Original version.

To quantify which sets are which, it seems helpful to count the sideways flowers on the 501s and count the solid white flowers on the 502 & 503.  An effective way to remember the combinations is whether they occur in odd or even numbers:

Original:
501 – 1 sideways flower, 3 petals, bottom right (odd)
502 – 2 solid white flowers (even)
503 – 6 solid white flowers (even)

New design:
501 – 2 sideways flowers, 4 petals each, top left and bottom right (even)
502 – 5 solid white flowers (odd)
503 – 7 solid white flowers (odd)

Alternatively, by counting all the flowers and/or dots, the Original set has exactly 5 dots on each piece: 

Original:
501 – 5 flowers, 5 dots
502 – 9 flowers, 5 dots
503 – 16 flowers, 5 dots

New design:
501 – 5 flowers, 4 dots
502 – 11 flowers, 9 dots
503 – 15 flowers, 4 dots

The following photo is from a 401 bowl, and it is here just to illustrate the terminology of ‘flowers’, ‘dots’ and ‘sideways flowers’ used on this page.

A sideways flower with 4 petals, top left.  Dots are located top middle and bottom right.  Two solid white flowers are evident, and in total there are 4 flowers in this sample.  This version of the pattern has no leaves.

Return to Pyrex Compatibles: Spring Blossom Green.