in reply to a couple of rounds of golf for the weekend

My solution for part 1 (209 chars, including 2 newlines):

@t=map eval"sub{\$n=~tr/1234/$_/;\$n}",((1243,1432)x2,1243,4321)x4;map
+{$n=
"1234$_";map&$_,@t}map{$_,join"",(split/(....)/)[1,5,3]}341221434321,
341223414123,342121434312,431221433421,432121433412,432124133142

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Using the list built in part 1, my solution for part 2 (358 chars, including 4 newlines):

sub p{my($c,$i)=@_;$i==16?$c?():"":(map("0$_",p($c,$i+1)),map"7$_",p($
+c-1,$i+1)
)}@t=map eval"sub{\$n=~tr/1234/$_/;\$n}",((1243,1432)x2,1243,4321)x4;@
+f=map{$n=
"1234$_";map&$_,@t}map{$_,join"",(split/(....)/)[1,5,3]}341221434321,
341223414123,342121434312,431221433421,432121433412,432124133142;$_=po
+p;for$m(
p($_)){++$s{$m&$_}for@f}print 0+grep$_<2,values%s

[download]

Hugo

In Section Obfuscated Code