I've recently got to GM status in carpentry and here is what I made to get there:
I bought up to around 30 carpentry real skill, 47ish shown.
Here is what I made to gm:
47 - 65: Ballot Box
65 - 75: Wooden Shield
75 - 90: Quarter Staff
90 - GM: Gnarled Staff
I think around 99 I made a few music stands and easels but I'm not sure if that actually helped or if I lost more boards that way.
It took me around 50k Boards to GM, give or take 5k.
I stood next to a trash can at a bank and just dumped everything in there with a Razor organizer macro called from my carpentry macro. The time it would take to make trips and sell the items made it definitely not worth it to me, especially with the vendor's paying less and less for goods they are overstocked with.
Is that real skill that your guide is based off of?