Call it what you will: "manuscript," "draft," or whatever. These are just words used to indicate something, just as we might call an item a "phone," a "mobile," a "cell," a "talk-talk," or anything else, as long as it's clear what we're referring to.
When it comes to Srila Prabhupada's books, "draft" is not the term we would prefer, because usually we think of an author doing a "first draft," a "second draft," and so on -- and we know that this is not the way Srila Prabhupada worked.
But if that's the term you'd rather use, fine. (Of course, we hope your intention is not to use the word merely for the sake of negative spin.)
Srila Prabhupada himself commonly used the word "draft" to refer to bank drafts, the military draft, and sometimes the drafts of letters or contracts, but hardly ever for what he wrote for his books. For his writings, he seems to have preferred the term "manuscript" (see examples below).
Hayagriva Prabhu, too, referred to such collections of pages as "manuscripts":
Alas, in the manuscripts (and I've been over all of them), not only the purports but verses 9/16-9/25 & 9/27 have been mysteriously missing from the very beginning (1967)." (letter from Hayagriva to Jayadvaita, October 15, 1970)
Anyway, whatever you wish to call them, we hope the meaning is clear: When we speak of "original manuscripts," we mean either the pages Srila Prabhupada typed himself, or the direct transcriptions of what he dictated, or various edited versions of his typing or dictation.
As mentioned above, by calling such pages "manuscripts" we are using the same word Srila Prabhupada regularly used. Here are some examples:
"My tape recorder, typewriter [were stolen]. Fortunately they did not touch my manuscript that I was writing, typing my books." Room Conversation -- September 30, 1976, Vrndavana
"[T]hen immediately send the manuscripts, finished or not, to the following address. . ." Letter to Brahmananda -- Delhi 22 September, 1967
"And regarding editorial work, I shall send you some manuscripts very soon." Letter to Hayagriva -- Montreal 14 July, 1968
"From this letter I can understand that texts number 6 and 7 are missing in the manuscript of the third canto which you have in Boston. The original manuscript is in New York, and when I go there, maybe in April, I will find this for you." Letter to Satsvarupa -- Los Angeles 18 January, 1969
"So far as correcting the manuscripts is concerned, you will edit first, then it will be composed, and if there are any spelling mistakes, that can be corrected by anyone there." Letter to Hayagriva -- 25 December, 1969
"I have done some translating recently, but it is not yet decided whether to send you the tapes or to transcribe them here and send you a copy of the manuscript. Very soon you will know about this. I will be encouraged if you keep on with the work of readying my manuscripts and printing them." Letter to Satsvarupa -- Bombay 25 November, 1970
"You may send the manuscript to Jayadvaita or Hayagriva for editing and printing with Dai Nippon." Letter to Hansaduta -- Jaipur 20 January, 1972