Seat Belts for Child Seats

[BlueDarlin]

Hi! I have a 2 year old and would like to drive him around in my 68 C10 once he gets a little bigger. I currently have some 3-point seat belts that I bought from LMC a few years ago. They work great, but donÂ’t have the feature of staying locked after you pull them all the way out. Does anyone know of seat belts that have this feature?

IÂ’ve seen one example on YouTube of someone welding in Latch points to the cab sheet metal, but IÂ’m not confident about the safety of this even though it looks very convenient. Anyone have any thoughts or ideas about this?

Thanks!