The Rebel was produced as a 250 and a 450, the 450 was only produced a couple years in the 80's.
The tank should be easy to find as they still make the Rebel 250.
But if the tank is just rusty inside, you can get a "Cream" kit to treat it and coat it and still use the old tank.
Bikebandit has a brand new 1999 Rebel tank list for $399 (#49532-001).....and it would come pre-painted with the factory decals on it ready to install
At 140 pounds you will be able to enjoy it for a long time if you don't get power hungry, and should net 60+ mpg out of it
__________________
Huck
Subaru Ambassador
92 SVX LS-Tour Magnaflow Exhaust, 5-Spd-AWD
88 XT6 AWD 5-Speed "Bride of FrankenWedge"
15 Impreza Premium Sedan
15 Crosstrek XV 5-Speed
My 5-Speed "How-To" Write-up
1976 Pontiac Firebird Formula
Current Count of Subaru's Owned.... "70"