That is solid maple from what I can see, I thought veneer at first glance too but its because they cut the tang off partially to fit the register.
I have oak but it looks very similar, chinese hardwood. A lot of it gets imported and sold at flooring auctions. Pretty good product, very durable, but not very many long strips. From what I hear even NA hardwood products are mostly short pieces now too.
I paid less than $2 a sqft at an auction about 10 years ago and it's still in great shape.
https://www.youtube.com/watch?v=Ejz3B7ik07Q
A circular saw can be used with care, or if you have an oscillating tool it very easy to do this. I had to patch some 100 yrs old maple that had water damage and my only issue was the boards had inconsistent widths due to age, quality control and shrinkage. You wouldn't have that issue.