Your best bet is to watch eBay. The cost of pre 64 Winchester parts have really gone up so expect to pay more than you want. There was a complete bolt on eBay last week and I think the selling price was about $350. Any standard bolt made from 1949 through 1963 will work. The late model safety design came in after 1948 which was anything after serial no. 121700.
You could save money in the long run by buying the receiver and bolt assembly from antleredacres and sell the one you have. The only down side I see to his offering is that I prefer the standard bolt handle. To me that bigger bolt handle would be OK for a target rifle but clumsy for a hunting rifle. The secret to buying a pre 64 Model 70 is that it's all about the condition of the metal. You could take his action, install the barrel, stock and scope of your choice and have a really good rifle. A 280 Remington 22 inch featherweight barrel or a 280 Ackley Improved 24 inch barrel really sounds good to me. It all depends if you want an 8 and a quarter pound hunting rifle or a 9 pound target rifle.
