I acquired a couple of bike frames and some of the original parts that go to them. One is a Mongoose from what I can tell it's late 70s and if I'm reading the serial number correctly it's a team Mongoose. It also came with the mag wheels, handlebars, crank and seat. The other is a GT Mach 1 Expert that I'm guessing is from the early 90s and it came with the crank and handlebars. I found the serial numbers on them but still can not figure out the exact yr and model for the Mongoose and the yr for the GT. Was wondering if anyone could help me figure this out as I have spent hours trying to do so and can not Pinpoint the info.

MONGOOSE serial #- TA { to the side of the serial number} 78592651

GT Mach 1 Expert serial #-S3HT1251