Expect the barrel's innards to be rough - don't forget, when that rifle was new, the ammo was blackpowder fired via corrosive priming, unlike modern ammunition.
I wouldn't be very aggressive when cleaning the bore, as the steels used in rimfires of that day are nowhere like the steels of today.
If you oil the insides after cleaning/etc, please don't stand it on end - lest excess oil drain into the stock wood over time, darkening and softening it in the area behind the action.
I also wouldn't store it in a typical soft gun case, as the linings can attract moisture, causing rust - although there are gun socks specifically treated for firearms storage.
.