Thanks for posting this.
The translation is correct.
The statement "Everything in the world we see that by God's spirit recorded prophecies are true" is awkward. Better: 'By everything in the world we see that the recorded prophecies inspired by God's spirit are true.'
And in the paragraph following [the translated excerpt], the Society begins by suggesting that one may have lost joy in the Service because of complaints toward the Brothers and Sisters... [they do not consider the possibility that one may have become disillusioned with the Society and no longer wish to spread the Society's message] They encourage further zealous field service by stating: " Don't allow anything to hold you back from remaining a joyful preacher of the Kingdom of Heaven. With the Prize so close, we cannot and may not take the chance."
(Nearly forty years after 1975, this sounds a bit ridiculous.)