Hi,
I agree with Norbsa, no need to replace valve seats.
But I would recommend an additive, I use Morris (superclean zero lead) with good results in all my classics.
Contact morrislubricantsonline.co.uk.
It treats 6 litres petrol to 20ml additive and I get no pinking and ride my Commando's hard.
Castrol also do an additive ,Castrol valvemaster which is popular in UK.
I would stay clear of the Fuel Cat,which you drop in the tank,once only treatment.
I tried this on two of my Commando's + other halfs Triumph Thunderbird & her daughters Triumph 3TA with the same result they all run Rough!!
It was a good job I placed some wire around the gauze as I could fish them out of the tanks easily & throw them as far away as possible.
Good luck.