Ouweneel does claim that F.C. Jennings denied the resurrection of the body, though I'm not quite sure if this conclusion is warranted:
Unfortunately, in 1927 he [Jennings] also published a book in which he actually denied the resurrection of the body, claiming that it will not be the old body that will be raised and renewed, but that the believer will receive another body. This caused much confusion.
(Het verhaal van de Broeders, vol. 2, Winschoten 1978, pp. 319-20)
Some thoughts about Jennings’s errors in his book „The Human Body” (link is above) are in Noel’s “History of the Brethren” vol. 1, pages 395-398. Perhaps Tom can help with the booklets by Elliott and others about this.
Martin
'The Faith and the Flock" magazine has his commentary on Isaiah during the years 1916- 1919 and continued in "Fellowship. A Monthly Magazine..." The first book version, I believe was published in either 1935 or 1948, probably by Lozieaux Brothers.