Scrounge some of the stick-on balancing weights from the garage next time you're in for tyres. They're even marked-up with a weight in grammes and come in several sizes.
Stick on feeder weights are available, they are in 5, 10 and 15grm I think.
There's a chap comes around local fisheries selling mostly floats, feeders and other bits. I have bought the stick ons, they work fine. Quid a strip.