Just picked up a Glock 26 Gen4 and now I will retire my Gen 3 to the safe as a "parts backup" piece. I've been googling around but can't seem to find any definitive answers to these questions: - Is there absolutely any parts between Gen 3/4 Glock 26 that can not interchange 100% reliably (besides mag release)? - Gen 3 slide works on Gen 4 frame? Gen 4 slide on Gen 3 frame? - Does Gen 4 trigger bar (with dot) work reliably in Gen 3? Thanks for any insite!