Yep, I'm with Ron too!
Damper blade friction is the first call for me as well, especially as you described wetting it and then it all went wrong.... water lubricated it perhaps or at any rate changed to friction element. The blades wear more than you may expect as do the friction areas mainly on the top clamping piece. you may find that the left side had been replaced at some time and the increased friction from the left as opposed to the right side is greater and a little wear has freed the right hand side to being effectively frictionless! A new set of blades and shims for both sides would be a good starting point. Of course a good check of all steering and suspension parts is also required! Plus hub security/adjustment too.
Your bottom cross head support bar you say is bent, Depending on the degree of bend it could slightly shorten the distance it is designed to hold at and this could alter the caster angle on that side, granted only very slightly but perhaps with poor friction blades it could at certain speeds induce a wobble. Think of a supper market trolley with a wobbly wheel yet there is no obvious damage. The steering geometry is not something akin to being made in NASA on a Morgan and if the support bar was structurally sound I would probably remove it and straighten it and at the same time see if the bend was caused by some form of impact causing the crosshead to push back against it. I can't or won't suggest exactly what you should do as I can't see the car and don't know your level of skill or knowledge but know this, your car was fine and this has just started so it looks like it can be sorted out!
Yes there are a myriad of possible problems and probably the cause will be a combination of issues. Steering box, track rod end/s, trackin, tyres maybe something lose! If you find an obvious problem then that's great but there will be an other issue that in combination has caused this to happen so don't stop checking when you've found the blindingly obvious, go through it all carefully. Don't stress just try and enjoy the process. The Morgan is a simple car and to some extent that is why these issues occur.
