That’s about right. Not just the larger OE offering called a 850. These are also a available in a actual 850 cfm or in a 1,000 cfm size. These will pop up on eBay from time to time.
Which one is that in the pic? Is it the air metered or solid fuel metered version? If solid fuel, I would love to know the calibration details, jets, bleeds, emulsion tube etc