Yes, the frame is the same but the front ends are a lot different. Mine is a 46 with a 41 front clip on it. What are some of the questions you have about it?
The axles are different if you are thinking of keeping the straight axle but they will interchange.
As for grills, what are you looking for? One to rechrome or one to paint? There are a lot of them out there still but I have not seen a new center grill available but then I have not looked either. MAC'S has a lot of parts for this car and good quality.
I have no problem helping answer as much as I can. I also have a buddy with a 41 business coupe.