This Tool looks to be in very nice shape, I put air to it and it runs excellent. 

I saw a new one online for $2200

Ingersoll Rand 7803-3B Series Milling and Sawing Motor

2200 Series, In-Line planetary gear, Multi-vane Air Motors. Milling motor versions ideal for applications with high side loading such as milling, cutting and de-burring. Fractional horsepower, 0.85 hp (0.634 Kw). 1200 rpm with adjustability through air controls not included. Stackable gearing allows additional gear reductions. 

• 7/16" - 20 Right hand threaded arbor
• Extra bearing support in the front end for improved side load capibilities
• Exhaust manifold and muffler rotates 360 degrees
• Will not burn out: Air motors can be stalled or overloaded for long periods without damage.
• Great for harsh environments: No heat build up or sparks make air motors ideal for use in flammable or explosive applications.
• Cool Running: A running air motor expands air, allowing motors to operate in temperatures up to 150oF and some motors up to 300oF with special grease, lube and seals.
• Compact and Portable: Get maximum horsepower in minimum size.
• Variable speed: You may utilize a wide range of speeds by using a simple valve on your input air supply line.
• Minimum maintenance: Our motors have a proven history of long, low maintenance life. All you need to provide is a clean, dry, lubricated air supply.
• No shock starts: Air cushioned start-up cuts stress to your equipment.

Thread Length is .549" then it steps 

up to 5/8" round x 1.366" long with a 1/8" keyway drive slot.

Overall Length is 12-3/4" 

Main body diameter is 2" 

Max 1200 Rpm 

Spindle Rotation is CCW as you face 

the end of the threaded arbor.

I don't know if this one is reversible

This might be the Serial number

SP07130243