I'm struggling to know how an exhaust fabricator capable of making manifolds like that doesn't know where to locate or what orientation to install the lambda bosses. They've put a couple of different bosses in and there are also pen-markings showing other potential lambda boss locations. Makes me wonder if these are a copy of something or they've tried to re-make them from photos on the internet and not been able to get the lambda position correct. If they had a GTA on site, then it would be easy to work out where they should go. But if you don't have a GTA engine to try the manifolds on, then working out where to position the lambda sensors would be difficult as you don't know the space available, routing for the wiring, access through heatshields etc.
Ours are a similar cost to those, but we're not going to have any available for at least 6 weeks now, we're absolutely flat out doing a load of Porsche manifolds & systems for another retailer.