Since creation, I have revisited this model, rebuilding from scratch to make http://www.thingiverse.com/thing:1336676. Please review both before setting on the right choice for your requirement.

I've seen a few tin lids, but no pictures of them in use and no precise idea of the size, so here we are. Unfortunately my unheated bed won't keep hold of this while printing. I'll figure it out, but in the mean time, I thought I'd release this.

If you think it needs tweaking, let me know.

The one example I did print (badly) in PLA was not pliable to be fitted over the top of the tin it was measured for. I suspect this would work much better with flexible filament. In theory, the lid diameter you need in the customizer is the measured width of the top of your can. You might want to add a little if, like me, you know your printer doesn't print precisely to the sizes you give it.

If you do customize this, print, and have success, please post a picture and name the customized object for the tin you're trying to fit. Something like, UK Baked Beans, or Cat Food Applaws Small. Have fun.