Can No Longer Feel Breast Implants After Breast Feeding

I agree with Dr. Rand. It depends on whether your implants are saline or silicone. In either situation, it is highly unlikely that you would have ruptured both implants. Therefore, it is more probable that the increase in breast tissue has masked the presence of the implants. It is probably best that you stop nursing for at least 4 months prior to having them replaced and it is preferable that you obtain your old medical records and surgery information if possible.

If you have recently stopped breast feeding, I would wait until the engorgement has gone down. This may take a few months.

With 20 year old plus implants the likelihood is that they have leaked. With saline implants there would be a deflation with loss of breast volume while with silicone implants the volume would be maintained.
If you have your implant information (Make / Model etc) that would help the surgeon decide where the starting point would be.