I've been surprised by how accurate the meter is on my Yashicamat 124, surprisingly reliable. I had no problem getting a battery replacement, not sure what it is as the camera's in Turkey and I'm back in the UK.
So for the cost it's worth a try you might be surprised. There's a couple of contacts that can play up they change the resistance for different ISO settings and is/was a known problem which was why Yashica later Gold plated them in the 124G.
Actually just like Roger Cole I was using my Lunasix or Luna Pro SBC alongside the Yashica and noticed the readings were the same