Cab 3 Point Rear Seatbelts - options

Hi, Does anyone have a solution for 3 point rear belts for a cab? I was going to buy a set from crazy quiff but the these are now £600 and I can't justify or afford that. Wife has stipulated kids can't go in the back with lap belts and pitched the car on the basis I could get rear belts sorted.

Anyone know of any other options or have a set sitting round they would sell?

Thanks

Are there the correct VW items, seem to be a lot cheaper if so?

https://www.mecatechnic.com/en-GB/reinforcement-for-vw-golf-mk1-convertible_C034480.htm?queryID=undefined&objectID=C034480&index=mecatechnic_en&queryString=155810401

I made brackets for mine my self out of 8mm plate welded in I might have photos.    What I can remember when get started easy enough job as loads room only fault if adults sit in back sure doesn't go over your shoulder.    Ok for kids and child seats

Thanks, it would just be for the kids in the back who are 10 and 11.

I've taken a punt on the parts above. Hopefully I can have these bolted in somehow. Just need to sort the belts etc.