I’d suggest you try taking it apart first before ordering anything, then if you find it like the cooker I had on my B36/2002, it was impossible to dismantle because of corrosion and seizure of the screws that held it all together. I ended up buying a new cooker and thereby saved money on parts that would otherwise become redundant and a waste of money.
Obviously if you can strip it down, then order the parts you need, but not until you know that it will take apart easily.
If you go down the route of buying a new cooker, you will find they come in varying sizes, so measure the slot where it has to go, height, depth and width and an allowance for the gimballing action, and then you will have all the details to hand when you let your fingers do the walking.