Varying pressures are normal, tho your spread is a little large, and #1 is kind of on the low side. There can be big differences between cold & hot engine pressures, so warm up the engine & recheck. If the numbers improve, it's just worn cyl/rings. Adding a little oil to low cylinder(s) and rotating the crank a few revolutions can help diagnose worn rings. A 5psi increase is not significant, in other words a small variance such as 5psi could arise just from slight variations in technique, not necessarily the addition of oil. Do the simple cylinder leakdown test - add compressed air into the cylinder at TDC (block the crank from rotating), listen to the exhaust (listen at the tail pipe), listen at the intake, open the rad cap & watch for bubbles, pull the dipstick & give it a listen, and pop off the oil fill cap in the valve cover and give a listen there. Bubbles at the rad cap is the kiss of death ( you will need to pull the head). Very small amounts of leakage at a valve can be normal and sometimes can be fixed by giving the valve stem a rap with a mallet - sometimes combustion deposits hold open or cock a valve. If that doesn't seal the valve, you can try checking the valve spring tension & maybe upping it a bit. Sounds of escaping air at the dipstick &/or valve cover indicates worn/broken rings &/or cylinder wear/scoring.