Crafsty, you have an Improved Meyer lemon tree, which naturally likes to grow more as a bush. I don't see where you need to prune it, except to prune out those poor branch stubs that must have been pruned off some time past. Prune the stubs down to the branch collar and prune out any dead stubs or branches. I would allow the tree to continue to grow. Not sure why you feel compelled to lop off branches, it looks just fine to me. Citrus don't really need a lot of pruning, except a little for pleasing shape and in older trees to remove dense inner canopy or dead inside branches.

Patty S.