If your bike came as a 6-speed, the dropout spacing is likely to be 126 mm so the stretch to 130 for current 8/9/10-speed isn't that much. Some riders just leave the spacing as-is and struggle slightly to fit/remove the wheel each time. Others have the frame "cold set" to make wheel installation easier. In fact, by the early 90's some frames were already 130 mm or 128 mm to allow 6/7 or 8/9-speed wheels to be used interchangably.
You will likely need a new bottom bracket along with the new crank but your bike is English threaded and has a 68 mm bb shell so finding suitable replacements will be easy.