Hi
My lwb Combi is going for conversion end of this month, it will have everything you require, the seats are Simora though rather than brick, but they are 2 + 1, all belts and floor mats
The conversion is being done by Knights custom conversions at Spalding, the deal I have done with them means they are retaining all the bits you need as Jon there said occasionally they get asked for a Combi conversion. So it might be worth you talking to them.
Regards
Mark