Did I get the Wrong Piston?

Just compared the old and new piston's for my '81 Husqvarna 61 Rancher. Substantial difference to say the least. Everything says it's the right one, they both have a B stamped on the top of the piston. Is this one of those progressive refinements or did the Greek send me the wrong one?
HELP
New piston is on the left

Get the Micrometer out and measure it up. I would guess it's an updated piston.

I would say its an updated piston. The change occurs from time to time in the motorcycle world. Perhaps it was found that less piston skirt provides quicker revving.

You won't know until it's in the cylinder but it looks like the timing might be affected. That can be a positive thing. Test fit it in the cylinder, if it checks out, then I'd go ahead and put it together.

I checked all the dimensions, everything is exactly the same except the ring is about .03 closer to the top of the piston. I recall reading something about this type of change to the piston skirt in the later saws, just wondering if it will work with the older cylinder.

Should not be a issuse gasket sizing should be check carefully just to make sure it does not smack the top of the head. (Pretty easy)