1st and 2nd jump into N

So I stripped down my R1 because it is jumping into neutral in 1st and 2nd, I found both gears to be heavily damaged. I was told that it's best to change 5th and 6th as well as it locks up using these gears, can anyone tell me if this is necessary as they both look ok to me. I was also hoping someone could tell me if there is likely to be damage to the second set of gears that lay underneath as again I've been told these are likely to be damaged but I can't see anything wrong.

If anyone has any thoughts on it, or know best place to buy the parts it would be greatly appreciated

Many thanks,

Craig

P.s. Merry Christmas