I rate it like this. Scott brand name has Brand Value three (BV3). The "B" designates this model as a B grade gun - Original Quality grade three (OQ3), except there must be some adjustment of the lack of ejectors. The Current Condition level looks to be one (CC1) - pristine, assuming the photos are for real and this is not a very good refinish. So, BV3-OQ4-CC1 = $8000. If it was an ejector gun it would go BV3-OQ3-CC1 = $10,500. $2500 may be too big a ding for the ejectors. Also, this grade gun in this level (apparently per the photos) is very rare. You might want to give it another 10% - 20% for very rare condition. I have noticed that very high condition guns are doing better than my predicitions at some auctions.
Hope that helps some. There have been a couple of Monte Carlo "B" guns in recent UK auctions - the catalogue archives can be researched. Let me know if you need more on this - time is limited right now, so it may take several days.
