Good idea. The plastic Simplex derailleurs broke frequently. I have a 1970s Stella (Artic....Stella-made bike sold through Artic Cat dealerships). I originally had two of them. The one I sold was brand new, still wrapped in crepe paper when I got it from eBay a year or so ago. The front derailleur (same one you have) was already cracked, even though the bike had never been assembled. I replaced the front derailleur and sold the bike on eBay for triple what I paid for it.