Info on Atlas RS-3 model #7090 undecorated

[rmangrum]

Have opportunity to purchase an Atlas RS-3 undecorated model #7090. Have not been able to find this number listed by Atlas as part of early RS-3 production. Did find #7070 undecorated listed in MR Jan 1985. These models probably have Kato mechanism. Seller says the loco has been in box for 15 years. Any idea what/when #7090 was made??[:)]