Thanks Mike. Those are great ideas. One thing we had gotten for him to add on was the Figure 8 pack. That is what he is running now. He sits in the middle of each loop crouching down at eye level.
He also got the grade crossing to drive his vehicles over and the bridge section. I recently purchased the FasTrack to O-Tubular transition pieces from Menards and I have lots of Menards track so the possibilities are endless. They are both looking to move to a different apartment in the Spring because there is no place to park on that street and she is freaked out about laundromats (with Covid and all). So they might wait on building anything that isn't modular right now. But the idea is great and they have room under their bed.
Regards,
John