Is my coin fake?

Hello experts

I have this coin but the metrics are not ok

According to Numista, Diameter should be 28.7, mine is 27.5

According to Numista, Weight should be 9.45, mine is 8.82

Also the branch on Britannia is very different

I see there are different berries variations, but the branch that is very different in each coin seems not even mentioned anywhere.

And the weight in the comments seems very specific 48 to the pound avoirdupois (1/3 ounce or 145.8 grains)

Given all that, should I consider my coin fake? Or were these coins just produced with such imprecision?

Thank you for any comment

I hope some UK coin expert will reply.

It certainly doesn't look like a fake to me.

Got another two coins weighted and the weight was

8.68g (1806)

8.71g (1807)

I think the weight on Numista is an error for long time a go

½ penny coins were nominally 9.45 g up to 1860 (according to Numista, but not SCWC).  7% light could be due to wear and weight tolerance and looks like a lot of edge wear also accounting for 0.6 mm loss per edge.

Also, SCWC says 9.22g. Don't know what to do with that.