The mixed image file formats were as presented in HathiTrust's viewer (
link). A searchable pdf based on those is here (
link - 36 MB). Perhaps unreadable pages could be supplemented by selective scans from John T's copy. WorldCat lists hard copies as being available at the British Library, the National Library of Scotland, the Complutense University of Madrid library, and the UC Berkeley Northern Regional Library Facility. There might also be hard copies in the Farnborough Air Sciences Museum archive or at Cranfield University.