Early 1900's home I am looking to put new sheathing on roof 3/8" plywood or 7/16" osb. At this time it has 1" planks 10" - 24" wide, various lengths no sheathing. Rafters are true 2"x6" hard boards same as the ceiling and walls. To give you an idea on age some studs have tree bark on 1 side. I have 2 questions about this issue. 1 - should I remove planks or just go over them. 2 - is there a air nailer capable of penetrating these rafters that would make the sheathing faster and easier? I have drywalled the interior and using a Senco screw gun snapped screws without having screw half way in, switched to 1/2" drill and heavier screw and break screw or strip head. After alot of trial and error tried nails which they just bent. Finally I had to pre drill each hole before fastening. Tedious, highly frustrating and time consuming but worked. I just don't want to spend 3 - 4 hundred on a nailer and have them just bend or jam the gun. I have never used a framing or roofing gun before so I was not sure how powerful or capable it would be for the job. Would be ran off a 60 gallon compressor, any brands in mind that would work? Thanks.