This is in line with what I have understood from my last hour's study of the most recent 10K and 10Q filings.
What misled me was the 10Q filing for 2018-Q1, which states that SIAF increased its equity interest in TRW from 23.89% to 36.60% during the fourth quarter of 2017 (page F-5 and 19), hence an increase of 12.71%. Since then it is my impression that the company consistently has claimed that its ownership in TRW amounts to 36.6%.
However, the 10Q filing for 2018-Q2 states that $43,289,545 of accounts receivable is to be settled by Tri-way’s shares included in the 36.6% equity shares that the Company (page 15). Thus a future operation.
Hence it seems reasonable to assume that, as you write, the fourth quarter swap was reversed (or possibly never finalised) and that SIAF currently holds the original 23.89% of TRW. I haven't found any documentation of this possible reversal anywhere though.
However, this still leaves the interesting question of what SIAF will own after the share distribution.
From what I understand of yesterday's announcement, TRW will swap USD 62,338,065 of debt against 18.3 M shares at a unit price of USD 3.40645. But this will, unless I miss something, leave SIAF with its current ownership of TRW which will be higher than 18.3%, though possibly modified depending on how many TRW shares there will be after the distribution.
Any views from the board?