[Alex Blair (RIP)]

LOw temperature solder ,650F...17,000 pounds tensile strength should do it..Can be used stainless,steel to steel, steel to copper,or any combination of the lot Called Stay Bright #8...High percentage of silver...
Special paste flux..
See your local refigeration supply house..They handle it//
Have lots of money in your pocket when you go..
Other wise just braze the neck on with brass,pre pasted Eutectic Silver....or arc it on ..MIG..TIG...stick...7018 or 7024 make a nice clean weld but an air craft heli arc welder would do an amazing job..Don't have an aircraft repair shop in your back yard..??