a few ideas for mt next OP Roller
The more I look at it, the more I want to cut down the seat post level with the other tubes. Then, make a seat pan like a motorcycle, using a metal rear fender just like with a motorcycle. Flip the handlebars, springer fork with disc, rear caliper or disc (if possible), remove coaster brake.
I think it would be a pretty awesome "chopper". I love these frames, as I see antique motorbikes in their lines.