Does the original Pro battery repair kit apply to Pro 7 Plus?

If you are talking about the battery included with the kit, most likely not. Considering how most laptops models have batteries of different shapes and sizes, especially if the laptops are differently sized from each other (e.g. a 14" laptop will most likely have a smaller battery than a 16" laptop).

However, the tools included most likely will work with repairing your Surface Pro, such as screwdrivers of spudgers.