Alenco...can of worms

I've been called in after 2 others "worked" on this window. Alenco non-tilt alum slider 45 1/2 W X 29 3/8 H thermal pane w mullion enclosed.

The owner said the channel balancers were replaced (so I don't know if they are correct. They are 1/2 " marked 2690 @ 29) Both top sash guides are missing. He noted to me that after the first guy installed the ballancers the window worked but was "sloppy" in it's frame. The Right channel balance top is broken so it will not catch on the take out clip. Once the left side catches on the takeout clip I am unable to remove the window either due to what appears to be a bowed frame as well as the right broken balancer catching on something (is not possible?).

What is my next move? Could you identify what I need from my description? Would pulling a near-by much smaller window and identifying it's balancer help?
thanks

den

OK I'll post those in a few days. Thanks
den

The 1/2 wide balancer (metal only) is 28 "

attached are photos of the ends and missing top piece. From my measurements and photos I have finally deduced it to be a Series 385 ballancer.

The 1 3/32 dimension of the shoe tells me it is a 15-004 and the 15/16 dimension of the top tells me it is a 19-005.

The top sash guide seems to be a 18-174

If these #'s don't seem to match the photos please advise.

Whoops forgot to list that. Since the window in question will require some extra work to remove, I got those specs from the window next to it which is the same height but half as wide. The bath scale said it was 12 lbs so I'm deducing that the window in question weighs 24 lbs.