Odoo version 13

I have a client, who has an accepted quotation. Its a closed quote. If I make a mistake, I can't charge it. But also i don't make a credit debt if i spend less of certain product

for example: 

I sold this items:

- 100 meters of product D

- 1 units product A 

- 3 units of product B

- 10 Hours of level 1 operator work 

- 4 hours of level 2 operator work 

Total amount u$s 100.- fixed and will never change. An invoice related to this is for the client.

I have another products related to this quote, which are not in the budget and that I would like to assign them to this quote, such as the use of screws that are in stock that were used and some others materials i forgot to put in the quotation.

I also have changes in the real world, but remember i can't change the quote for the client 

When i finish the work i got some changes:

- Use 1 additional product A 

- I did not use 2 B products (I had a return to my stock) 

- Spend 2 additional hours on level 1 work

- Do not use 1 hour of level 2 

Is there any way to get this flow inside the system?

Thanks for your time!

Emiliano.