I tried the Piko glue from the pink bottle, a liquid that works well for small parts ( same bottle for over 3 years still worked great yesterday!! I use Quik Grip for larger items as it can be easily peeled off years later, great for gluing the USA motor block in the Bachmann trolley.
I have recently been very successful with BONDIC, its not a glue rather a bonder after using the UV light pen.
I recently bonded a nylon bushing on the underside of a LGB locomotive frame to extend the support column of a truck.
Worked very well with little surface to fasten to.