I had checked in my Parts Supplement for the Sunbeam “260” & “289”. In Section MF Suspension – Front, there are no stabilizer bars listed. That implies that the Tigers use the same as what came on the Series IV and V Alpines.
I also looked up the same information in my Alpine Parts manual. In Section M Suspension – Front, there are two part numbers for Stabilizer Bars. 1201492 is listed for Series I and II, while 1210473 is listed for Series II Le-Mans and all Series III. In Section MA Suspension – Front, 1210241 is listed as the Stabilizer Bar for Series IV and V.
Unfortunately, the diameters are not listed for any of the stabilizer bars.