Okay I had a look out back and I'm right out of parrots...... I got a slug!
Sorry just went all Monty Python there for a sec.
Seriously, I've got a 50MB, 105MB and 240Mb all Quantum Prodrive LPS. (made in Japan) These each weigh 450g.
I've also got a 1.1GB Quantum DSP3107L which is Malaysian made but it's 500g so the postage will be more.
The 2 Quantum Fireball 2.1GB units I' rather keep for myself.
So if your willing to pay the postage from Oz, around $25 (16GBP) with tracking and postpack. I'll bubble wrap your choice and send it to you. They all have 2.1 OS on them. I'm guessing your A500+ is std 2.1 ROM ?
I tested each drive on my A500/A590 for a little while and they work fine(apart from the standard SCSI HD whine. Arrh Compact Flash cards, so nice and quiet).
As with all old HDs all it takes is one drop and "crunch" paper weight. But the Quantums do head park and seem to be very resilient. IMO. No guarantees..
Anyway, let me know if you want me to send one over the water.
Cheers