cobra trailer brake lever gas strut failure?

It appears that the gas strut on the brake lever of my cobra trailer
has failed. Today I noticed the lower end was no longer connected
(apparently the bottom pin detached from the fixed connection point),
and it was just hanging loose by the top connection. In addition, the
strut seems jammed in the extended postion. It rotates ok (with a
little resistance) but won't collapse any, even with a *lot* of
pressure.

Any advice for repair/replacement? Is this a cobra-only part, or will
any gas strut of the same length and throw do the job? Is the cobra
part available at finite cost?

TIA,

Frank (TA)