I've built the kit twice in the last 20 years or so and the only major problem I ran into was aligning the booms. Other than that, fit was above average and the
possibility for extra detail is excellent. It's also a "tail-sitter" and will require weight to sit properly on it's gear. I put the weight where the weight is on the real
thing---in the engine nacelles. It will take a little more weight there but the main
gear can handle it better than the nose gear can.
BTW---The Mid America Air Museum recovered a crashed P-61 from New Guinea
some years back and is restoring it to flying condition. I don't have the exact URL
to the museum here at work but any good search engine will find it under
"The Widow's Web"
Ray