Works by Fred Stone and Robert Wilson were among the 40% of lots selling above their low estimate at Rago 'Art Unlimited' auction on May 1.
The show has been indefinitely postponed only weeks before it was due to open.
The museum has lost two key figures already this year.
Prices for the work of the husband and wife sculptors have soared in recent months.
Works by François-Xavier Lalanne and Bruno Paul were among the 86% of lots selling above their low estimate at Phillips 'Design' auction on April 30 in London. The sale totaled $4.65m (GBP3.44m), exceeding the pre-sale high estimate.
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