Clint,

Welcome to finishing with lacquer.

Usually, if you fuzz the paper, you didn't get enough clear on before the fillercoat (primer). I usually use 3 to 4 unthinned coats of clear on the paper, then sand it mostly flat and touch up any spots where I fuzz up the paper and sand those areas again. I get a decent matte finish from the clear. Then I shoot primer and sand off everything except what stays in the low spot. If I still have low spot (not a usual occurrence since I tend to go pretty heavy with the primer), I touch those up and sand. Then I shot a coat of very thin (like 80% thinned) clear on to lock the primer down. At this point it should be pretty smooth, but if you manage to still have some low spots, hit them with some more primer, sand and recoat with the thin clear. It can be a tedious process.

This is where I am with the classic plane I'm working on. It has 3 coats of unthinned clear on and I'm sanding because I didn't do the best papering job in the world (I let myself get in a bit of a hurry). So I'm having to sand a lot of paper overlaps. Once I get it sanding down and pretty flat, I'll hit it with another coat of clear and sand again.

Once you are happy with the surface, after the coat of thin clear (don't skip this step or you'll regret it when tape pulls up the substrate), you can use what is called a blocking coat. It's basically a thin coat of some color to give you an event colored surface to paint on the base color. When I've shot red, I've either used silver or gold as a blocking coat. I like it better than white because white is the heaviest color there is.

If you are concerned about weight, the only real answer is backmasking (can you spell tedious?). The idea being that there is only one layer of color on the plane. You tape and spray each color without going over any color. It saves weight but as I say, it's tedious and time consuming.

Clint,

It sounds like you're doing exactly what needs to be done. Following tips is the first part, but development of the techniques is what eventually makes each one easier and better. The sand through you discribe is something everyone who has ever finished over silkspan, silk or tissue has had to learn how to avoid or minimize. Believe me, with practice you will get to a point where you know by feel and sense where and how much to sand. Even learning what the correct texture looks like takes time and experience. No set of tips or instructions will produce a good finish for you until you develop the techniques and skill. Stick with it and you'll do fine, it sounds like your on the right track to learn the things that can't be taught, only experienced.

The two biggest problems I've identified is not getting enough clear down first before touching it with sandpaper, and not paying enough attention to all the little imperfections before silkspan goes on. Two mistakes I won't make on the JVL Chipmunk.
 I'm sanding off the last of the prime and I think I'm ready to put down the white base coat. I'm actually getting happy with it now.

The two biggest problems I've identified is not getting enough clear down first before touching it with sandpaper, and not paying enough attention to all the little imperfections before silkspan goes on. Two mistakes I won't make on the JVL Chipmunk.
 I'm sanding off the last of the prime and I think I'm ready to put down the white base coat. I'm actually getting happy with it now.

This is where technique comes in Clint. Its not a mater of abandoning the sandpaper early, its a matter of which paper to use and how much. I start sanding after the 2nd coat, some areas after the first, but if you watched me you'd wonder why I bothered at all. Removing "nibs" and stray fibers is the reason. It only takes a swipe, not concentrated sanding. This helps because if you wait, you get buildup around the fibers and nibs and that makes the surface harder to level. This is why your finish starts when you start thinking about a new model, not after you've framed it up.

Glad you're liking you work on the Mustang, looking forward to PIX!