Well, I've never met a model that couldn't benefit from a razor saw, so my answer will be unabashedly biased. (Can I use "unabashedly" in advocating kitbashing?) If the mogul is original and mint (and in the original box, etc.) it
may be worth it to list on evilbay to see if you can sell it for enough to buy a newer one and perhaps a few extra pieces of rolling stock, but whether it's worth the trouble is up to you.
Personally, I don't worry about "collector value." Besides, by cutting one up, am I not making the rest even more valuable for the collectors?
Later,
K