Yes do check to see if it’s a collectible one first.
The Torch Site in the UK does some drop ins for them, plus you’ll find some on ebay.
Not a lot of money and will make it a usable torch. Just don’t expect it to blow you away. And while the drop-ins are cheap. Just remember that an entire Convoy S2+ in working condition can be bought and shipped to your door for less money……
If it isn’t a valuable Mini Mag, then consider a p60 upgrade. Pretty easy mod and will make it a very useful little torch.
But the vfm (£ performance ratio) is still fairly low. So do it fun, not for money reasons.