Sounds like she's a keeper... or at least her DAD is!
Wish I knew the size... I have an '80 Jag. You could check part numbers on Brown's. That might help you cross it to another year/model at least.
BTW- I was looking for your sled on Brown's. I don't think you have a '78 Lynx. I see a 71, 72, 74, 79, and 80. That's it. Maybe you have a '79...???
2004 Polaris Trail RMK 136
1997 Ski Doo Summit 500
2000 Arctic Cat ZL550 ESR (in NY)
2000 Arctic Cat 440 Panther (sold)
1980 Arctic Cat Jag 3000 F/C (in NY)
"If it ain't broke, take it apart and find out why!"