My grandmother had kerosene lamps all over her country house because of power failures and habbit from the days before electrification. The question "Will they start" made me smile.

My suggestion is to use the a few times a year just to get used to them before you actually need them. Be careful not to lower the wick so much that it falls into the oil reservoir - grandmom did that once while the wick was lit and there was no way to recover in her cut-glass lamps.

They've been sitting for 7 years, so use them.