Please could anyone recommend a period- and cost-appropriate chainset and derailleur combination for a late-1970's/early-1980's Puch Alpine? I bought it on eBay a couple of years ago with a SAKAE SA chainring, a SACHS HURET front derailleur and a SUNTOUR ACCUSHIFT 4050 XCE rear derailleur. See photos attached. The rear derailleur isn't the original one, and I'm also not sure about the chainring. I've had the frame resprayed and am in the process of sourcing the other components. Many of these will be NOS to match the originals, but I'm less concerned about matching the original chainset and derailleurs, whatever they may have been: Cost isn't an issue per se, but it's a relatively low-end bike and I'd like to get something fairly basic to match the style of it. Perhaps a "matching set" that's been proven to work together reliably over the years? I’m happy with the original ten gears and their ratios, but would also consider having six at the back and/or a compact chainring if that broadens my options. Any thoughts gratefully received. Thanks.