Hi Jane,
Maybe I will take you up on your offer next year (I am out of growing space this year), but thanks for the kind offer.

Are the plants so overgrown that you must prune them now ? I am asking since the best time to prune forsythia is late winter before they start to bud. At this time, you get maximum flowering, because they flower on "new" wood (similar to newer roses). As opposed to azalea, mophead hydrangeas, etc which should be pruned right after flowering (because the bloom on "old wood" and thus you will cut the blooms off if pruning too late in fall or in early spring before flowering). However, not so with forsythia. Forsythia bloom on "new wood" so pruning in late winter is actually recommended.

Of course, anytime you can get in the yard to revitalize an overgrown shrub, but just thought I would mention.