French language Q&A Forum

I want to translate the following into French:

When I had signed the letter, Maurice mailed it.

I would write this:  "Quand j'avais signé la lettre, Maurice l'a envoyée."

What I want to do is avoid the pluperfect in the subordinate clause. l reached for the usual stand-by "Après avoir/être + past participe" but that will not work here, as there are two subjects (I have always used "Après avoir ..." in the context of there otherwise being one subject) and "Après avoir signé la lettre, Maurice l'a envoyée" means "After having signed the letter, Maurice mailed it" but it also means that Maurice both signed it and mailed it.

 That is inescapable because "Après avoir/être ...", a hanging participle/dangling modifier, lacks a subject, which is provided in a sentence by the first noun in the main clause, thus there is no doubt as to who signed it - it's Maurice because of the operation of that principle. (At least, that's the case in English; if French is somehow different, please tell me.) 

I then tried "Après que ..." but I still end up with the pluperfect because inescapably the signing of the letter is complete and precedes the posting of it by Maurice.  Then I thought to use the passive, but that seems generally to be anathema to the French and it is really clumsy to try it here.  Then I thought to change the exact English formulation of the sentence and use "J'ai signé la lettre et puis Maurice l'a envoyée" but I don't think that that helps (nor is it correct). The signing precedes and is complete before Maurice's action and I keep ending up with the obvious - passé composé for Maurice's action and plus-que-parfait for the action that preceded it (signing).

On reflection, I suspect that I can only resort to the passive to solve this problem:

Maurice a envoyé la lettre qui avait été signé par moi.

(It doesn't matter to me that the passive is anathema to the French; this is just part of a grammar exercise.)

Do you think that that is correct or am I missing something in my quest?

Any solution please, other than the passive, to re-write the original in a way that avoids using the pluperfect in the subordinate clause?

Les livres desquels je pense sont remarquable. The books I am thinking of are remarkable; the preposition here is de.

Referring to “vous adorerez cette autre idée : modifier un pyjama en flannelle défraîchi.”

for

“you will love this other idea: making alterations to a pair of faded flannel pyjamas.”

I can only find “flanelle” (one “n”, not two) in the dictionaries. And this is a female noun. So should these answers all be “…en flanelle défraîchie.”?

The text reads “Tant mieux, car je n'ai même pas encore commencé à râper le fromage”, but there’s no “même” spoken in the audio (Cécile has confirmed this to be the case in the Q&A). 

The text just needs a small correction.