just one thing to note if you use a type of seal that doesn't swell at all - it will need to be the perfect size otherwise it will leak. I've not used the Yokomo seals but the RDRP seals are the ones I always used and they worked really well.
They come in a pack of 16 so there's enough to do 2 full cars for £4.79
http://insidelinemodels.com/inside-l..._category_id=0
Kev Lee