8708 refers to the specific model number/floor-plan of your coach. You can go to the factory site to get quite a bit of sales brochure type of information from prior model years.
OR.... It could be that the other owner was part of a RV Club and that was their club number. But in this case you are right as it is the model number.
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David
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'08 Tour Master T40B
MBE900 Diesel (Mercedes)
08' Saturn Outlook Toad
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