Does anyone know if I can fit a K1100LT EXHAUST SYSTEM on my K100RS without major surgery? I would hope that a few brackets etc would do it. Any ideas?

Yes, it can be done and yes, it is only the moutings that need surgery. If you woul call it major or minor, depends on your surgery skills. The exhaust manifold measures are the same at least. LT exhaust has one disadvantage, it is one piece from the manifold to the silencer, so it is prone to cracks, if not mounted 150% tension-free. If you have K11 footpeg-plates, you can use the standard K11 mountings, imho that is wehre the different mouting has its reasons.

That is why the system I am co-devloping with Keihan consists of 3 parts [ downpipes, 4 into 1 collector and "normal" silencer [ 50mm inlet]. It can be used for the k100 [ collector and silencer ] or all 3 parts for the K1100.

Originally for my Streetfighter [ Underseat ], we then developed a "normal" replacement from the 4 into 1 collector - fits with pegs, panniers, etc.

I went to the factory at the end of last week to sign off my underseat system. The replacement system is being priced up at the moment. Material is TOP quality stainless steel. The attached pix are of the prototype - before finishing and polishing.