I wouldn't classify this as a conversion. It's just a refin. Nothing had to be routed and the neck wasn't reset. The original serial number would have been lost during the refin (looks like it was a darkback from the control cavity shot). A '57 goldtop would be up around $200k and a recent refin would bring that number down considerably, but it does appear to be an old factory refin so that price might be close to its real value, provided the 'story' is accurate.