Herman Miller Soft Pad EA219  

Dear Design Lovers,

I'm new to this forum but not new to ageless design 🙂 I would need your help on understanding something. I have an opportunity to buy vintage Herman Miller Soft Pad EA219 chair but there is something I'd like confirm first. I have already one older version with updated base and this particular one I've been offered doesn't have any height adjustment. 

I've always thought initial versions had a basic "screw" adjustment and later versions came with a gas lift system. Now, my question is if this chair is built combining base from one chair and a seat from another? Or is this legit? Picture attached. 

*edit: asking price USD 850

All help much appreciated 🙂

Best,

Lundi