For my own education, I looked at various datasheets including the ones from Epcos. They make a reference that S10 are available in 5.0 mm lead spacing.
This leads me to believe they make custom parts for manufacturers like Fluke, but not widely available to the general public? With a 5.0 mm lead spacing, it is possible that the diameter is also less than 10.0 mm?
You can try and bend, fit the bigger MOVs, possibly 12.5 mm in diameter according to some datasheets, into place.
One alternative is to desolder the K575 MOVs from other Flukes so you get the proper size for the tight fit 87V. Then use the bigger diameter replacements in another Fluke where you have more space?
For example, here are pictures of the Fluke 117 from Dave's review. As you can see, there is a lot more room for the MOVs.
http://www.flickr.com/photos/eevblog/sets/72157626631973147/PS. My Fluke 113 uses the same 05, K575 MOVs from Epcos. Diameter measures less than 10.0 mm.