Working aircraft allloy

I’m hoping a few of you will know this, but how do you work with older alloy skinning and thinner guage parts?
Been trying to get some of the damage repaired on my GR.3 but finding that the skins and other cockpit structures are fairly brittle and won’t take kindly to too much bending and knocking about.
I thought about applying heat to the effected areas, but thought this made alloy even more brittle?

Any info will be very useful

Thanks in advance, James