I have been in contact with Terry Woodward and can confirm
Fig 5 "Cranked" vertical lines should be hidden detail of the cutout in the angle to clear buffer.
Fig 5 Overall width of buffer beams should be 8.75" as per text
Fig 4 Bend should start 5.625 from rear of frame and return to parrelel 1.375 from that point as shown on Fig3
Fig 3 "Box" around cylinder mounting holes should just be lightly dotted to indicate position of cylinder.
Terry has also emphasised that despite what the bold intro says that this is not meant as a blow by blow construction series with working drawings but an article about how he went about building a unique subject, if anyone wishes to have a go at doing the same engine then as mentioned in the text get the drawings for the other engines mentioned and work out the missing bits to suit your own requirements.
J