ID help needed, 20" girls bicycle, probably Murray?

[Starnger]

Hello everyone!
Someone wrote me on Facebook asking to ID his vintage American bike.

I immediately thought of Murray, since this is a very specific tube connection they used. But then there are more pictures:

Somebody used New Departure C coaster tab with the D hub shell? The drop-outs look 40's or 50's with those chain tightening bolts, definitely not like typical Murray spiky ones. Older stem and sprocket makes me think it is a early 50's bike someone put a 60's banana and sissy-bar on later. Can anyone ID it more precisely? There is a plate with the number under the BB, but it does not seem like a regular Murray numbering system.

Thanks in advance!

 

[Robert Troub]

the sprocket and fork crowns don't look like Murray....a frankenbike for sure

 

[Coyote]

the sprocket and fork crowns don't look like Murray....a frankenbike for sure

Agreed.
The sprocket is similar to one on an old Rollfast 20" that I have.
The fork crown cap is found on Ross, but not Rollfast.

A closer look at the headbadge area/shape would narrow the frame type down.

 

[Starnger]

RustyGold at RatRodBikes identified this as 1949 Shelby frame. From the pictures of other bikes like this i could find online i very much agree.