340 with A/C lower pulley ?

There were both made. Addon pulleys were common to aftermarket or dealer installed a/c. Your pic does look like the addon type. There is really only one way to know for sure. I'm thinking the last one piece 3 belt pulley offered here was priced at 40. The addon should be worth 30 if the rubber isn't totally shot.
I might make the A/C operational again someday so I better hang on to it. A/C is not needed where I live but I do travel to some hot places. It does have the Airtemp sticker on passenger rear side glass, and A/C is on the build sheet. But with a non original engine who knows where pulley came from.
Thanks for the info.