AJ is correct that it can be tied back, but it will act strange because the trans will think you are a wide open throttle all the time.
It won't hurt the trans, but it wont shift until the RPM's are pretty high and then when it does shift it will be a hard shift.
As long as you know it going to do this, it can be tested and driven this way.
You can tie it back 2/3 of the way also, and it will shift a little more normal but then it shouldn't be driven with more than about 2/3 throttle. (see the relationship there?)
Obviously it should be hooked up when you can get it done.
If the fluid still looks nice and bright red, it may be just fine and runnable.
Since you are missing those parts, you may consider a Lokar cable setup instead.
Or if we know exactly what your current setup is missing, there are people selling this stuff on here all the time.
You will need the parts specific to your combination. (Engine and carb type)