Radiator Bleed valve

[someonelse]

Becoming increasing hard to bleed the rad as the valve has got worn so the key slips.

If I turn off the valves at the bottom either end I assume just a little water will come out if I remove the valve completely?

If I then take it to plumbers merchants, are they likely to have a replacement?

 

[dilalio]

Can't really tell from that photo but it doesn't look like a standard vent! I'd take it out and post a pic of it and see if you can identify the rad manufacturer!