Hi, here in the u.s.a. the 3 main suppliers of vintage spider parts are Midwest Bayless, Vicks, and auto ricambi, I don't recall if any of them sell new replacement wiring harnesses but you can check...in addition , I see used complete harnesses on ebay all the time. There's also universial automotive wiring harnesses on ebay and other sites if you need to go that route...for my 55 chevy I bought a painless brand kit where each and every wire is labeled where it goes...so there are options, if it was me I would look for a good Uncut used harness perhaps from ebay as close to your model year as you can to keep your car stock unless your planning modern upgrades with electronics...hope this helps.