I'll stake my reputation on it
to risk harming one's reputation on someone or something.
from McGraw-Hill Dictionary of American Idioms and Phrasal Verbs
Your idiom sounds like it's a reference to putting a fingerprint on something to prove one's identity when signing it. As in, I won't just do what's required (putting a thumbprint on the document), I'll go above and beyond to excessive lengths (put all ten of my fingerprints on it). I like this idiom as a translation because it captures the sense of putting one's legal identity behind the project. I like the lesser known variant, I'll stake my name on it, even better, but it barely passes the Google test which might make it too obscure. "You have my word" is another, similar idea.
For a much more direct translation:
to/until/till the bitter end
continuing until the end of a particular situation or period of time, even though it is difficult or unpleasant
She remained loyal to her husband to the bitter end.
from MacMillan Dictionary
This implies that you will stay with something or continue working on it even if everything goes wrong. Note, saying this doesn't imply that you expect things to go wrong, just that you would persevere if they did.