I've never made buckboard bacon... However, when I make regular bacon, I use about 2.0% salt, 1.5% sugar. 3% salt is as high as I'd ever consider going with salt, I just don't like anything that salty... I'd likely never go above 2% sugar either, unless maybe I wasn't planning on ever frying that 'bacon'...
Your recipe is almost the opposite relationship with sugar... yours is 4% sugar, 1.5% salt. You could leave that cure for 10 weeks and it'd never get very salty.
If your fine with that much sugar, then keep doing it... but if it were me, I'd increase the salt to around 2% and reduces the sugar to not much more than 2% . I don't like really sugary bacon, because it tends to make this really messy sticky goo in the bottom of the frying pan.
Your 0.3% cure #1 is just a tad bit higher than the USDA would allow in 'bacon'. Now, in Ham, they allow higher, so if you don't 'fry' it like bacon, your amount is not much of a issue, even for USDA. However, for bacon, your supposed to be like 120 PPM of nitrite ( and no nitrate), this would be 0.192% cure #1 ( 1.92 grams per Kilogram of meat/water).