I know a fair bit about exhaustion of intellectual property rights under EU law (US first sale doctrine is similar). It sounds like you need something on property law?

It's not property Lyds, but thank you :)

I know an awful lot about the employment agency regulations in Singapore, but it sounds like you need something different from that.

can I interest you in some case law on deaths caused by dangerous driving by sleep-deprived truck drivers??

This is just a contractual interpretation point isn’t it?

Someone drafted something without properly explaining what they meant by “exhaustion” and now you have an ambiguity (or at least are potentially arguing for an ambiguity, see last para). So it’s all basic contra pref and matrix of fact type stuff as to what the people meant. 

Even if you could find a case where someone else had failed to provide a definition of exhaustion you’re looking at a facts issue rather than a law issue I think?  So I’m not sure case law in relation to that word will be particularly helpful. 

FWIW statutory restraint doesn’t sound much like exhaustion in the context of a physical thing which will actually be exhausted in a physical sense at some point. You seem to be twisting the language of the contract to even open it up as a possibility. 

Yeah joshing aside I don't have a clue what the question being posed in the OP is, I'd assumed it was something construction specific as I'd not heard of a concept of "exhaustion". If there is no such thing, then it sounds all a bit what Mal said