Well you've got an early "sandcast" frame number mate, but as has been said, without the correct engine, it's only a parts proposition.
You say it's missing the carbs and oil cover(?) what else is missing? The frame is worth money, as is the forks, tank, (if it's the very rare wrinkle tank without the carb dimples it's worth around $2K) oil tank, speedo and tach, wheels, brake disc, master cylinder, rear shocks, seat, in fact, pretty much everything. If you can't find a correct engine, you can still sell it for parts and make some money. Cheers, Terry.