一道语法题

春暖花开

In 1933 the rubber,clothing,and shipbuilding industries put into effect a six-hour workday, not as a temporary expedient but as a seemingly permanent accommodation to what many observers though was an economy made overproductive by advances in technology.

正确答案填完是这样的，不明白的是though was an。。。。。。
什么用法呀？句子结构怎么是这样的 not as。。。。。but as。。。。。 what 。。。。though  was。。。。

是倒装吗？还是was 为印刷错误，应该是as？