commercial yellow cad is relative inexpensive, you just want to do every single part at at the same time as they batch it. do all nuts bolts, brackets, lines, ect. you want to specify they use "brightener" to get the correct shiny finish, ask for samples of their work to make sure.
technically I dont think it is cad anymore, but zinc due to epa regs..
Soda or walnut would be best, even glass will change the surface, esp the valve cover. paint stripper would work very well also, just messy but lowest cost / higher labor for you.
IMO even the Eastwood paint just doesnt look right.
I went all the way in and got my own copycad plating from Copy Cad® & Zinc Plating Kits - Plating Kits - Caswell Inc
cost me about $500, pm me if you want details, fairly easy, but lots of variables to get finish you want. Will consume a lots of hours to do. upside is you can plate anything you want when you want and not have to take every single part off, catalog and document so that you know where each nut bolts screw washer goes. The long fuel lines can be done but will require creative way to make tanks long enough.
we discussed this some over here. yellow cad plated or not