Murphy, you should do like I done, order what bolt heads you can from Tichy train group, and Grandt Line cause they make the best, I think Tichy is a little better, but Grandt Line has more, then after you get all theres, then contact Hobbylinc.com and from their home page type in pls then click go, and hunt up their hex rod, on the Plastruct, it should be the cheapest you will find.
Cause the bolt heads you make yourself don't always look the best, but the ones from those 2 companies are pretty good, then what sizes they don't have you make yourself, cause you got no other choice. Don was great with me from Tichy train Group, you couldn't ask for better service, I had my bolt heads in 2 days from when I called him.
Hope this helps.