Hi Digger,and welcome. On your next build,try using 1/16 pins for your pipes and barrel underlugs. It took me a couple early attempts at this hobby to figure out that tis best to use as least a screw , pin bolt as is realistic, thought being is it looks better, and you can always go next size up if need be, or the dang thread tap breaks off in some hole. ,Ask me how many?
This is one area of the build that used to give me the willys,til I started moving rr pipe back more,and got an idea as to lining up the sides to bring down with the files,etc.
You can save this challenge, and by doing so ,add a new lesson to your book.
Have a goodun, just back off ever now and then and get a cold one or two------ Dave