Hey I'm learnin, first time on. 1- Invader Date of MFG. 1-20-77 , can be seen at World Snowmobile Headquarters, Eagle River Wisc. Invaders 1-79, 1-80, 2-81. Intruders 2-78, 1-80, 1-81, 3-82. LTD;S 1-80, 4-81, 1-82. Interceptors #73, #517, #572. Some jump on and ride, rest in rebuild stages. Lets keep up this great site I'm learning a lot of good info. Thank You.