Interesting that the extra .5v of the 675 batteries doesn't make a difference in meter accuracy but one more volt does! I found 675s at the local supermarket at $10.99 for an 8 pack. Definitely more economical than the Wein cells!
Am I correct in believing that unlike the old mercury batteries, which maintained a steady voltage till death, that the 675s would gradually fail, and thus start giving meter inaccuracy with the dropping charge? I'd probably just replace them at a set interval anyway but my geek side is interested.
Thanks for all the info!