The very back of the presser bar lifter arm is broken off of my 1222E pfaff sewing machine can it be replaced

SOURCE: Model 6230- presser foot lifter won't move presser foot

That's the problem seized up use a penetrating oil from the top and work it up and down and it should free up

SOURCE: lost instruction manual

ebay

SOURCE: PFAFF 1222E Sewing Machine (~1977). Mechanically Locked-up

You might be in "Stopmatic" mode. Check if your pressure lifter bar is in the upper most position, if it is the machine is disengage and you are set to wind your bobbin. Lower it to the 3 o-clock position this will engage the machine and the needle will operate.

SOURCE: presser foot lifter is stuck can i fix it

If you can't lift the presser foot up at all undo the presser bar screw on top of the presser bar, if you have a dial turn it to 0, you should now be able to move the lever, if it is still tight put some WD40 on the presser bar and leave it for a couple of hours.

SOURCE: I have a Pfaff 1222E sewing machine which needs a new motor

Good for you, to repair a great machine instead of buying some more modern, disposable machine!
I found a generic motor that will fit your machine at http://www.pfaffmachines.co.uk/partsDB/index.php?function=detail&recordID=185. Free delivery within the UK, but that doesn't help much, does it? There's several places in the U.S., like http://www.a1sewingmachine.com/parts.html http://www.sew4less.com/QuickSearch.php http://sewingpartsonline.com/
You'll probably need to look for a generic motor for your Pfaff, but they should be out there.
I did check eBay; they do have generic sewing machine motors, but unless you're very experienced with eBay, I'd be very careful there.
Check with your local sewing machine dealer/repair place (even if they don't carry Pfaffs). Maybe they can help.
Good luck--I wish I could be more helpful, but let me know if anything I've sent helps, ok?
Robbie