I've already sold that frame, but I have a Nakamura Shadow bike I'm about to disassemble. The sticker on the frame says Nakamura Light Weight Series. I can weigh that for you if you're interested.
My 1992 Kuwahara Lynx. It's an entry-level model that came with the Exage 400 LX groupset.
The bottom bracket is a bit unusual, it required a Campagnolo tool to remove.
I think I want to put a different saddle on it and maybe upgrade to the M560 groupset.
On the Alta they used a piece of teflon cable liner inside the tube. Some more pictures: https://budgetbicyclectr.com/new-1995-mongoose-alta-mountain-bicycle.html