Wellington Beekeepers

Can anyone spare a 3/4 brood frame? One of my hives hit hard by mites despite having Bayvarol in for 5 weeks now. Down to one box and bugger all brood. Have changed treatments and will also get some formic acid in there, but am in need of giving the brood a boost. My other hive is full height so can't swap a frame over. Any help greatly appreciated. I'm in Brooklyn.