Hi Jim, I'm guessing you found a sand filled sub build? Only one I remember posting about cutting and buffing, but that would have been automotive urethane.
Lots of info on the web. Unfortunately some is utter crap.
I'll tell you what I know.
I think the Behlen lacquer is nitrocellulose (often called simply nitro). Nitro has some great properties for speaker finishing, less so for other things because many modern finishes are catalyzed which adds speed to curing and enhances durability. In a production setting, the speed is important. A project like yours, patience will be your friend. Simply put, a good finish takes time, both for curing and "finishing" the finish.
It can be sprayed coat after coat without much concern for total film thickness. That's the plus side. The down side is because it's not catalyzed, it takes a long time to really cure hard enough to really work with a buffer. I'd probably wait a month after last coats...longer if it's possible.
I don't know the grain structure on Tineo never having used it, but a really smooth, flat, high gloss "piano" finish requires grain filling. That can be accomplished with lacquer, but the process is long with nitro...it just doesn't have the body and solids content that is present in commercial finishes. Spray, sand flat, spray, sand flat, lather, rinse repeat...more times than many have patience for.
Jim, you should understand that I differentiate between a high gloss finish and a "piano" finish. First will show grain when looking at it with glancing light. Piano is like glass...absolutely flat.
I think the biggest problems people have spraying finishes in general is not getting wet coats and not taking enough to complete. We're just accustomed to rush, rush rush, but I suppose that's touching on a personal philosophy of mine. With most finishes, the ideal would be a film thickness that's just shy of running and sagging. A hard thing to accomplish. With nitro though, if you get a run, it can just be sanded flat and recoated.
Excluding a lot of variables your finishing schedule might looks like this.
Sand what you have FLAT with a hard rubber block or similar.
Repeat process a few times. You need a significant film thickness to be able to sand and buff.
Once you've got it where you want grain fill wise, set it aside for a few weeks, then cut and buff. Enjoy the journey! I remember reading a long time ago that finishing is the boondoggle of woodworking. We tend to rush the very thing that will be most visible in the end game.
If you're a reader, I'd recommend "Understanding Wood Finishing" by Bob Flexner. Probably the single most informative reference I've encountered. Demystifies a lot of finishing folklore, I still refer to it now and then even though I've probably had it for 20 or more years.
Also some good finishing info from Jeff Jewitt at Homestead. http://homesteadfinishingproducts.com/
You could also look at the wood finishing forum on Woodweb, but it's primarily pros using products the DIY market never sees, plus there's folks there that seem to patrol for DIY's so they can scare them away.
Hope that helps you out. FWIW, I prefer to have this info "in thread" so everyone reading can potentially benefit. Feel free to cut and paste in yours if you like.