1949 Frame question

[Darby]

I am looking at a 1949 frame for sale. All numbers and casting Mark's appear correct. However the horn mounting blocks have rounded corners. Palmer's book indicates these block had square corners for this year. The frame is not flattened in this area. Any ideas if this is an original frame as discribed? Thanks!

[1950Panhead]

1949 frames have 18,19 on the neck, 8 and 12 on axle clips, horn blocks vary.

[duffeycycles]

If you look close at many '49-'50-'51 frames you can see other differences like the thickness at the rear axle plates