I'm assuming you are aware of this, but an open weight model is not an open source model. I've heard it compared to having somebody hand you a car engine versus having the blueprint to build the car itself. An open-weight model does not provide you the training data that was used to teach the AI, does not provide you checkpoints for the AI during training, and doesn't provide you the code that makes up the model itself. The only model I am aware of that is truly fully open source is OLMO from AI2.