"period interpretation" beethoven?


I was at a wonderful classical music store in northern Indianapolis a couple of weeks ago where they told me about some relatively recent (15 years or less) performances that had benefitted from scholarly study into beethoven's forces and tempos. Unfortunately, I have lost the paper on which I wrote this down... anybody got a pointer to who this might be?
blw
I would generally agree with Jhold on period practice, although for a majestic 9th I would reccomend Furwanglers Bayreuth perfomance. The strange thing about the fast tempo period conductors is that the 1930's performances by Toscanini are the closest to them in tempi and phrasing.
Pls1: I second Furt at Bayreuth. Even though the sound of the chorus is strange (coming from below) due to the Bayreuth stage.
Also recommend Furt's '43 recording of the 5th/Berliner (DG).
Finally, I'm not sure Bwl's referring to Harnoncourt if it was back in the late '70s... admittedly, I'm not a fan of "period" playing! Cheers!
The Harnoncourt Beethoven with the COE from around 1990 is worth a owning, unlike most "period" Beethoven interpretations (and I like period playing, especially for Haydn).

RE Furwangler 5th. The 1943 is excellent. I slightly prefer the 1937. There is an excellent transfer available from Biddulph.
I'll track the Biddulph down. Thank you! Furt's 1937 was my "ref" 5th (picked it up on tape fm the local radio).