Toymakers' Stocks Hit Lows on Downgrade  NEW YORK (Reuters) - Shares of top toy maker Mattel Inc.  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MAT.N target=/stocks/quickinfo/fullquote"&gt;MAT.N&lt;/A&gt; and rival Hasbro Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=HAS.N target=/stocks/quickinfo/fullquote"&gt;HAS.N&lt;/A&gt; fell to their lowest  levels at least 14 months on Monday after a downgrade by Lehman  Brothers, which cited deteriorating industry conditions.