If you can afford $8.00, you can grab a copy of "Aerospace Projects Review" ev2n1. It has a long article, including several drawings, on the Pluto.
See:
https://aerospaceprojectsreview.com/ev2n1.htm
If you are not interested in the history, some drawings are also available.
https://www.aerospaceprojectsreview.com/catalog/drawndoc.htm (search for Pluto) for $3.00. As far as I know, these drawings are the same as some of the ones in the article, but it may be beneficial to get this even if you buy the article. These are PDF's of the full D size drawings. The article only comes with pages formatted for 8x11 and 11x17.
The only problem with these drawings is that, while scale, they do not have individual dimensions. The pages have a rule on them but you will have to derive the dimensions.