Stainless steel 44 Magnums are called Model 629, not Model 29. As a practical matter, it makes no difference, as the internals are the same.

S&Ws do not use a "transfer bar." A transfer bar rises up when the trigger is pulled and the hammer strikes the transfer bar, which in turn strikes the firing pin. This is not how the S&W revolver mechanism works.

S&W uses a hammer block, which prevents forward travel of the hammer unless the trigger is pulled.

You can clearly see if it is in the revolver by simply starting the hammer back and watch for it to drop out of its upper position.

If it is really not in the revolver, then I suspect that some unqualified person removed the side plate and carelessly allowed it to fall out, and either did not realize it or did not know what to do with it. A very small number of gunsmiths have been known to remove the hammer block in the erroneous belief that it makes a smoother or lighter trigger pull on double action. A competent gunsmith can smooth out the action just fine without removing such an essential safety component.

If any part is missing, there is no telling what other dangerous or unsafe operations have been done to your revolver. You should send it back to the factory to have it properly repaired. You should not sell it without an essential safety-related part. That is both irresponsible and dangerous, and could be grounds for liability.

If any gunsmith or other person tells you that removal of the hammer block is not dangerous because of the hump on the rebound slide, you must immediately place all advice from such a person into "File 13," or "Category B," as all advice from such a person should be considered suspect.

The hammer block is essential to the safe operation of the S&W revolver in the sense that the revolver WILL discharge if it receives a sufficient blow to the hammer, whether that blow is from someone hitting the back of the hammer with a hammer or whether the blow is from being dropped. It is unsafe to be on the shooting line with a person with an S&W revolver modified by removal of the hammer block as it is impossible to predict the direction the bullet will travel if the revolver should discharge under such circumstances, and as much as these wags will insist that no competent shooter will ever drop a firearm, it does, and has, happened.

GET IT FIXED. WITHOUT DELAY.