That works out to about 14cfm, which is in the ballpark performance wise. If I remember correctly, these have disc valves which ride directly against a seat cast into the aluminum head plate. These were removeable, and I think individually available, but the general idea was to replace the entire plate and valves as a piece. I still think this is a B6000, since the 5000 is listed as a 3hp pump. The shape of the crankcase and intercooler is also a closer match.
B6000 Pump Parts, B6000 Pump. Repair parts for B6000 pumps used on S71-AT32,7580B,C07Z080 air compressors
mastertoolrepair.com
If there isn't any obvious problem with the compressor like excessive oil pumping, I'd use it as-is. It's a bit small for abrasive blasting, so you will need a very small tip. This is not an especially durable compressor though, so be aware it might give its all on this job. Use a good quality oil, and keep it well ventilated with a clean air filter to maximize its chances. Most likely failure point, imo, is the valve plate, so a spare wouldn't be a bad idea.
FWIW, I always hated working on these things. The flywheel was an absolute ***** to get off, since it didn't use a key and was forced onto a tapered shaft by the center bolt. It was also quite fragile and would tolerate no excess force to get it off. The many fan blades prevented getting a puller behind it. You also had to remove the base pan and invert the whole pump to get a ratchet extension with a hex driver on it to remove the bolts holding the block to the case. These inevitably require he-man twisting to get the bolt and aluminum threads to part company. Then, when it was all apart, you had a hell of a time digging out the remains of the base gasket from the recessed top of the crankcase that it sat in. So what I'm saying is, if it ain't broke, don't fix it!