Psych Overcall in a Singleton Suit

Playing rubber bridge against GIB, I am in third seat, not vulnerable against vulnerable. Partner passes, East opens 1, and I find myself looking at this:

10xxxx
9
xxxx
Jxx
I decide that East-West are making something big, probably in hearts. Surely a game, maybe a slam. My only defensive values are ... well, not much, but what about a sneaky 1 overcall? Maybe it will keep them out of a good heart fit, or maybe it will mislead them in the play.

The auction proceeds as follows:

WNEMe
Pass11
34Dbl4
Pass5DblPass
PassPass
I feel vindicated by West's strong 3, but partner's 4 is not especially pleasant, and East's double is even worse. Having made my bed, perhaps I should sleep in it and pass, but I decide to run to spades. Apparently partner doesn't get it, and when his return to 5 is doubled, I pass, because I'd rather play 5 doubled than 6 doubled.

Partner's hand turns out to be

xxxx
Q10xxxx
xx
x
and we end up taking one spade and three trumps for down seven. That's 1300 points their way. Ouch.

But have you seen the bright side? East-West had 13 top tricks in 7NT, for 1720 plus the rubber bonus. Unhindered by us, I doubt they'd have had any trouble bidding it, either. What a great sacrifice!