For Sale Mamiya RB 250mm lens, with issue

Mamiya RB-67 250mm f/4.5 lens. Pre-C. Aperture has one lame blade. Simple fix, especially if you have the repair manual on hand and/or know how to get into these shutters. Lens is otherwise in good shape. See pix. Make offer. Cash, check, or money order. Shipping from L.A., CA 90042.

$40 or best offer.USD
Price : 40.00

Does this affect stopping down, or just the shape of the aperture?

The lens stops down, but the aperture maintains the shape shown in the second picture.