What kinda of wood or other material should be used to replace the box end and soffit?
Fibre cement sheets would work and very cheap.
Treated timber Hx.y, I forget the minimum x.y you'll want for exterior cladding.
Would Home depot ProWood 3/4 in. x 4 ft. x 8 ft. Ground Contact Pressure Treated Pine Performance Rated Sheathing Plywood work?
Ground Contact Pressure Treated
Higher spec than you need but it'd be fine.
Home Improvement
Fibre cement sheets would work and very cheap.
Treated timber Hx.y, I forget the minimum x.y you'll want for exterior cladding.
Would Home depot ProWood 3/4 in. x 4 ft. x 8 ft. Ground Contact Pressure Treated Pine Performance Rated Sheathing Plywood work?
Higher spec than you need but it'd be fine.