fietsbob

denomel is off in a non reality if they think glue is welding..

JB Weld is an epoxy + aluminum filler, Adhesive, not welding..

But , Here is a possibility, It involves converting headset type to Threadless.
You need a quill extension. Its a steel tube with a quill wedge at the bottom, to tighten inside the fork, a mechanical reinforcement as half the extension tube doubles the inside if the fork, were it able to take the whole headset , the original Quill stem can go in the top.
That was it's original purpose
If you have enough fork exposed above the top of the frame to thread the upper race in,

But not enough to put the lock ring-Nut on, this is possible ,
But It is not going to be the strongest thing.. [Huge Understatement]

JB can fill in the threads, to bring the surface back to smooth to bring tube OD back to 1" , the tube quill adds 3 inches .. Its just a filler , there is still the weakness of cutting the threads.. buying list,
a threadless headset, + you buy new stem , a compression cap , to adjust a threadless headset and perhaps new bars.

Buying the appropriate fork is best, or hiring a machinist/ framebuilder can properly weld on another section of tube.

Bernie Mikkelsen, Oakland Cal I think can do this .. cost : a couple hundred + is reasonable .

But I suspect its not a Collector's bike you are restoring..

I wouldn't ride that, better to spend the money on a new fork.

I have added height to a threadless steerer tube with a mechanical fix,
using a quill stem raiser , from BBB in NL, it relocates the headset adjustment to the
top as before .. , core is beefed up a foot long and so the spacer stack is quite a bit longer , and the bars have a handlebar bag beneath them on a 2nd stem.

but the original steerer tube was already long enough if I were 25 and flexible , the stem sat on 3 10mm thick spacers, , so there is good support for the scheme..

Its not a Down Hill bike , a JRA bike ridden by a 63 old guy with no speed ambitions..