I think I would agree with Bruce - it would be a very nice engine with a full restore especially if you go with the ball bearings and pulleys. However, I do understand wanting to keep it fairly original - I only have one copper colored firebox Jensen which has been well used and shows it but since it belonged to a good friend I don't want to destroy the patina (and the memories).
I was curious as to the consensus of repainting these. It seems some don't care for the pinkish paint, but this has just enough color washed out and burned into make it a few shades lighter and rather nice(almost the color of the old Bing brickwork). But the rust in every nook and cranny are more concerning, so I guess it gets a paint job.