Hey guys, sorry if wrong forum for this. Recently started to fix up my MTB, and found some old derailleurs in the shed but don't know anything about them other than they work heh, hoping someone can point out the best ones to use.

These are what I am currently using, rear and front, front one I have no idea of the brand.

These are what I have to choose from, rear and front, the right front derailleur has no screw to seperate the parts so I can't get the chain in unless I take the chain apart (no tool for it), one on the left does. The rear left one I think I got a very long time ago but may have been an expensive one.

Not very good at taking pics. Thanks for any help.

We need a pic of how the current Rear derailleur mounts to the frame.

That SUntour looks like the nicer one, but it's a claw mount, which will need a semi-horizontal dropout for it to be used. The other one (the shimano) looks to be a standard mount, which will require a derailleur hanger on your bike....the hanger seems to be still attatched to it.

Here is a full picture of it I just found hopefully not too dark, looks like it's on that dropout thing you were saying about, been so long I have forgotten pretty much everything to do with bikes :/ So will I be ok with the claw derraileur and the left front derailleur?

Thanks