Wheel spacers......or not?

Hi all, apologies if this has been gone over before.
I have a 2001 (Y) Td4. When I bought it it had 17" alloys but I recently bought a secondhand set of 16's off an 03 I believe, for winter tyres.
I fitted the rear ones today and they seem to be really close to the drums. On looking at the 17's they appear to have a bigger offset.
The drums are dished in the middle so I'm wondering if I require to use a spacer or something to bring the level out to flush with the rest of the drum.
Any advice welcomed.
Thank you.

what does this have to do with your engine?

Absolutely bu***r all, but allow a newbie a mistake please.
Where do I find the freelander wheel bit?

they should fit ok if off an '03 but i suspect they are off an earlier version that had smaller drums.

only fixes are to fit spacers or buy some real post 2000 rims

Thanks Freelaner. Appreciate the advice.