[...] It is no wish of mine that you should withdraw from further participation in the execution of your own designs for scenery. I have proved to you that it was my wish to maintain pleasant relations, favourable to the progress of the work, between you and the gentlemen who had actually to carry out your designs. At this juncture it is not for me to try to throw light on the reasons why this eventually proved impossible. [...] My one actual wish is that you and I, two honourable men, should part—for the present—in peace. As to the question of the compensation to be paid you, it belongs to a department which I must, if I am to maintain the resolution necessary to carry through my whole enterprise, leave wholly to the conscience of the trustees for the financial side, men who are pledged to the strictest economy, while remembering that I, for my own part, have ruled out all idea of profit.
As soon as Messrs. Brückner have definitely decided to proceed with these decorations, I promise you to consider how you may be compensated in future, when profits accrue on your (moral) copyright, for your share in the work hitherto. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 669