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The bike is rough - surface rust on the frame and the bottom of the fuel tank. The gearbox took it of the road with grumbling bearings...
May as well yank the engine and start with the frame refresh. Your comment about rust on the fuel tank's bottom is worrisome. If the tank was not completely drained and dried prior to storage, the rust
could be due to water in the tank that has slowly eaten through the steel. Perhaps remove the tank and use an inspection mirror and a flashlight -torch- to look inside. With the R65's single petcock, most rust issues initially show up on the opposite side. Also check for bits of the OEM tank liner material that may have flaked off.
If the tank is dry, add a bit of fuel and monitor the underside. During your rehab work, keep an eye out for a good used tank.
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