It must be a great feeling to know you kept this tree alive and well for over 30 odd yrs, I hope my trees are as fortunate one day, very inspiring to us young folk.
I hope there is one thing that inspires you through this entire process. It does not matter how long you have been doing bonsai, if you expect your trees to change, you, have to be willing to change. If you grow you can make your trees grow and if you change you can make your trees change.
I can speak only for myself but I can see the same things in many people around here. You get stuck in a rut thinking you know as much as there is to learn so you get comfortable in this one little level. You start to think your trees are wonderful and you get pissed off is someone seems to suggest they may not be. Instead of considering something you argue why it is not so.
It may be that a critique is correct and the flaws in the tree should be considered, it may be that something else is at work. But: You have to know yourself and most of all, be able to consider the artistic impact of what has been suggested. If you do not understand the art everything else becomes esoteric, and if your reason for rejecting a suggestion is based on you concept of the art then you should be able to defend it.
However I am not suggesting that you jump in wiith pruners and chain saws in an attempt to conform a tree to someone else's vision, especially if that someone is stuck in a similar rut. Or, if that vision is beyond your ability to see or accomplish. If that is the case then you know there is something for you to learn; learn it. From all of this and from all the offers of advise try to glean out of them---concepts.
No matter how long you have been doing bonsai ultimately you are your best teacher. You can follow a bonsai master and learn everything he has to offer. What do you do after that? At some point you have to find yourself and your own vision. A great teacher can inspire you to do great things but a great teacher cannot, by his or her presence, impart "the magic touch" giving you the ability to produce really great bonsai without you having to do the work, or you acquiring your own vision. That really is the most valuable thing you can achieve. You can have all the skill, tools, books, wokshops, horticultural knowledge and a loving mentor, these things are all like boxes of serial in the store, that can be purchased, but they cannot give you a vision that is your vision. I have seen that around here. I have seen it in myself and I can see it in many. You can spend $10,000 on the most fantastic piece of Yamadori the world has ever seen and, without the vision of what to do with it, turn it into kindling in an afternoon.