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Ahh! More information!

6-12 laps aren't a lot really, try just keeping on honing. Give it 20, shave, then 20 more, etc. The Naniwa is probably cutting better than you think it might be, modern...

The Norton combo stone is less than $95 US here in the US, so that's going to be hard to beat for value.

Film will be the cheapest option and should work for you though you might want to use...