I would have someone TIG weld a threaded stud on the bolt handle.
Remington is noted for its porosity in the handle so threading it is sometimes hit & miss.
Phoenix Custom Rifles did mine. Fast turn around and top notch work from them.
If you worried about porosity send it to Short Action Customs they'll reinforce the threaded end.
I used the search function instead of starting a new thread, I'm getting ready to send mine out and was wondering if anyone has done one recently, that they might chime in as well.
LRI did my bolt and bolt handle . Unbelievably great customer service, tracking of progress of job and shipped back. It literally only took them 48 hours and it was on its way back to me.
I will be sending them more stuff to work on for sure.