I have found plans for seven similar Grant designs.
Edwin T. Hamilton, Complete Model Aircraft Manual (1933) presents Grant’s Minute Man Tractor in Chapter 21, page 219. This is a 21″ span model with 1/32″ sheet surfaces.
Gary Hunter’s The Plan Page includes a series “Fundamentals of Model Airplane Building” by Hamilton (1934), using Grant designs, that includes No. 4, a 20″ span pylon model with 1/16″ sheet wings and 1/32″ sheet tail surfaces, No. 5, a 17 1/2″ version of the Cloud Tramp with all 1/32″ sheet surfaces and No. 6, a 26″ version with 1/32″ sheet surfaces.
Grant’s Aero Science of Free Flight (1941, 1983) includes a design for a Stability Stick Model, Chapter 13, page 325, that is a 24″ span version with 1/32″ to 3/64″ sheet surfaces.
Chronologically next is the Cloud Tramp (1954) with 22″ span and 3/64″ surfaces.
Last is the 21″ span Basic Test Model using 1/16″ balsa or 1/32″ hardwood presented in Grant’s Gateway to Aero Science (1979). This book is still available from the AMA book store.
A half size Cloud Tramp built from the half size plan is also an excellent flyer. I’m afraid to push mine too hard outdoors, because I could easily lose sight of it.