If this is a standard Colt receiver, then any, and most likely most, Colt slides will fit just fine. But that doesn't mean there might not be some fitting involved. The Colt's were pretty much made to the Ordnance specs that required parts interchangeability. Again another but; we must assume that there are no drop-in parts for a 1911 type pistol.
You post that you have a Model 70. Do you mean a Series 70? Series 70 slides appear for sale on ebay as well as GunBroker, problem is most sellers do not want to ship overseas, and in some countries importing gun parts is restricted. Also our goofy US State Dept has a rule that any gun parts with a value over $100.00 (US) requires an export license.
Now I'm no expert on this, but just trying to pass along some data that I have seen or learned about this issue. I personally have sent small gun parts to other countries, as well as reloading stuff I have sold on eBay. But a complete slide is kind of big and a bit weighty and might arouse the curiosity of the customs inspectors.
Somone here on the forum might have better advice or wisdom than my lengthy post. The little issue is finding a slide, the bigger issue is getting it from point A to point B without a lot of problems and hassles.