My Win 94 30.30, made in 1974, has a top eject system, probably like your's. Because of my weakening eyesight, I need a scope...but probably won't have one installed because I like the open sights for quicker sighting of game, and I want to keep the Winchester "look", which doesn't include a scope.
Weaver makes or made a side-mount system which mounts the scope to the left of the bore. It works ok within .30-30 ranges if hunting, but the offset plays havoc with paper-punching if the ranges vary much. My FIL just traded his mid-seventies Mod. 94 with scope for a Stevens .243.
i inherited a 94 from my father that is scoped...... a weaver detachable sidemount with a 2 1/2 power scope (i think its a weaver, but can't positively recall)..... i put only a few rounds through it, and it seems to work fine.....
i remember worrying a great deal about the offset, trying to figure out how i should sight it in..... the reality is, as toolman stated, unless you are going for headshots on field mice, or shooting paper, it doesn't seem to be a problem. just sight in for 100 yards...... with a 30-30, you're good to go......
I Tapped the top of my bolt and mounted a Weaver base and use a Beemans # 3 scope. This is short enough to allow ejection without the spent case hitting the scope. I don't lever with the stock at my shoulder so there is no poke in the eye working the action.