I just wanted to share this . I purchased new grey door panels for my 51 1300. They didn't come with the holes for the arm rests or marked in any way.I took 2 1/4 -20 nc bolts and sawed off the caps then proceded to grind the cap side to a cone shape leaving about a 1/16 flat round spot on the end.Boy they get hot fast! Then I screwed them into the door leaving them out about 1/4 inch. Then I fitted the new panel on and using my hand I applied pressure to make an indent.Remove the panel again and there will be 2 nice indents on the inside ready to drill.The fit was very precise.The drilled hole was a bit raggy but the arm rest covered it.Next time I would try a 3/8 leather punch for a cleaner hole.