[mothered]

Can it be larger than the item I want (if doing wrong item method) or does have to be smaller?

If I may answer.

In terms of size, provided the wrong Item fits In the original package of the SE Item, then that's all that counts.

Ok thanks, do you (or anyone else) know of any items that weigh around 7kg, struggling to find one

I wouldn't know offhand.

As with every SE, I'd need to research It.