Need help to know the value of these items

And this Sugden pre amp.
https://servimg.com/view/20105590/37
https://servimg.com/view/20105590/36

I have to clean my system.

to clean the panel frontal metal and cover top I not use aggressive chemicals but only simple neutral soap three new and soft microfibre cloths, make two cloths damp with water, one must also have a little loose soap, run over the entire surface if it is level, rinse with the second cloth and dry with the last cloth.
If the dirt is stuck in the knobs and in places where it is inconvenient to pass the cloth just use ONLY a clean and new painter’s brush and dust.
To give an example: if the arm is very dusty, just pass a new painter's brush with soft fibers lightly dampened with water, then gently dry with a soft cloth
To clean the contacts you can use deoxidizing sprays, or isopropyl alcohol (in Italy where I live is in the pharmacy) DO NOT USE a alchool disinfectant, that is greasy and not good, use cotton swabs to pass every single contact.
to clean mobile speakers only dry microfibre cloth and dust

If you look on youtube you are looking for tutorials for all these little problems.
simple example
https://www.youtube.com/watch?v=eRRzGEMgIHA
https://www.youtube.com/watch?v=ohyRBZSIXpw

TY best-groove.