The unit does have some rust on the case corners which you can see in the pictures. It also has a mark on the case but the synthesizer itself is in nice condition, especially after the work which was done on it. Again, the unit was maintained very well and kept inside at the college. It is fully functional and tested by Phil Cirocco after all of the work was completed.
The final revision of the ARP 2600 saw the synth adopt the black-and-orange livery of latter-day ARPs. This offered numerous internal improvements, most significant of which was the demise of the epoxy-encased circuitry of earlier models, which made these 2600s relatively simple to repair. 2601 v3.0: Late in 1980, a final revision was released with un-potted submodules, making them easier to maintain, and a revised suitcase. However, these late models are quite rare as their release coincided with ARP's final days. The critical circuits of the early 2600s were cast in epoxy blocks that are almost impossible to repair.
Around 1975, ARP switched to potting the circuits with silicone rubber, then topping them with epoxy, which is less difficult to repair. A few years later they stopped potting altogether, resulting in circuits that can be easily fixed. (Mark Vail / Bob Moog in ARP 2600 Most Popular Modular Synth in: Vintage Synthesizers, page 128) ARP 2601, ARP 2600, Synthesizer, Vintage, Orange.The item "Rare ARP 2601 V3.0 Vintage Synthesizer with Orange Lettering (ARP 2600)" is in sale since Tuesday, September 06, 2016. This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Synthesizers". The seller is "billyntish" and is located in Bainbridge, Georgia. This item can be shipped to United States.