<VV> PG fixing broke snap ring

[cfm]

The snap ring holding the pressure regulator spring assembly broke while I was disassembling and cleaning the valve body.
Vendor "C" is out of stock, (probably years) (I like the nomenclature, so personable).
Vendor "U" doesn't list.
So, two simple questions:
The snap ring profile looks a little special as compared to a similar sized sample and the local hardware store. Following the circumference of the broken ring itself, it gradually gets wider than returns to a more uniform width. Was this intended by GM or may I get your blessings, oh wise men of air, to go ahead and purchase a "modern-looking" snap ring? I have this feeling that it s intended as the extra width holds the spring assembly in the bore.
If not, does anyone have a "parts" Powerglide transmission lying around wherby I can obtain said snap ring? Market pricing will apply.
-chris mann