Welcome to Drummerworld. I too, have been having troubles imputing Yamaha serial numbers into their search engines. And I've tried 3 different ones.
Perhaps just type the badge serial numbers out here. Maybe a photo or two of your kit.
So, for example .... my rack tom is TT 714 D .... and that means it's a "tom tom", 7000 series, 14" and dark wood finish. On dating my drums, it seems the dark wood finish was first offered in the 1982 catalog ..... so my drums are 82 or later, and that would make the shells Agathis/Phillipine Mahogany.
Doing a quick "google" for Yamaha drums MQ and what pops up are Marching Drums ..... field drums. Now, if the MQ is followed by 3 numbers, the first number will denote the series (7000, 8000, etc) and the second two numbers the size of the drum (12", 14" etc.) That's is the letters/numbers are on the left field of the badge. If the MQ is in the right field of the badge ..... then that's a date code. And that's the part I'm having trouble with, for my drums.
Both of my computers fail now, to connect with drumarchive.com ..... but a two days ago .... I got all the information I have about shell make-up from there. Perhaps the site is down ..... or perhaps the computer gods just hate me. So, you might try there. They had a ton of Yamaha catalog computer scans.