Hmm. While the above is true, I'd say the 2149 has more in common with the 2152 than the 2150. Looking at IPLs from 2001-2002, only minor things differ - bottom end is the same, chassis, chain brake, down to the cylinder bolts. The cylinder, ring and piston differ, of course, and the 2152 has the Zama carb which means it also uses a different intake, but as long as you don't mismatch anything, all these parts will swap over between the two.
So to some it up, the 2152 and the 2149 share the bottom end. The piston and cylinder are identical with the 2150 and 2149, chain brake parts are the same from the 2141 up to 2153 (and mayb 2159) and the cylinder bolts are the same for ALL Jreds.
Using parts from the 2141-2145-2150 saws would be a lot more of a hassle. They have screw-on rather than snap-on tops (2007 IPL), clamshell bottom ends (2141-2145 cylinders won't fit a 2149 for this reason), and all have Zamas (again, 2007 IPL). This being said, the EPA 2150s up to serial# 030103001 do share the cylinder assembly with the 2149, same Pn. Crank is different for 2141-2145-2150, but the needle bearing is the same and the bearings should be the same size. Looks like they have different seals in the plastic cases (makes sense...). And of course you all know the mighty Husqvarna 346XP also shares a lot of parts with the 2149, and this P&C will bolt right in for some more revs.
It will also bolt right on to a 2150.
Sorry to be ranting, but this is my favorite saw we're talking about here! I have cut fresh and dry pine, elm, birch, dry planks, most everything for firewood and nothing seems to slow it down, and it also isn't too heavy to be lugging around in the middle of summer. I don't know what kind of firewood you have to deal with, but the saw pulls 18 inches with ease, and for firewood that goes a long way over here.
I have seen people having different opinions on whether this is a true-blue, bona-fide, gen-u-ine professional saw or not. I personally couldn't tell you how this saw would handle heavy use over long periods of time, but I sure wouldn't be afraid to try it. In my opinion, this is first and foremost a really good saw, no matter if it's semi-pro or pro-pro or pro-lite, or whatever. You know what they say about the red ones...