That Yamaha Motobike from the '70's brings back a lot of memories. I knew several kids that had them. I myself had one of the AMF "Evil Knievel" bikes
As BMX Bikes became more popular I ended up stripping everything down to the bare frame and painting it red and adding mag wheels. To make matters worse about 10 years ago when I was back home picking up stuff I had stored - I hauled that box of Dress Up Goodies to the Dump. - I know , I know I could of sold them and bought Models..
Hope things have been going well for you lately. I sure enjoyed this Fantastic series on the Merc. and have learned a lot. Hopefully by dredging this up out of the depths you may be Motivated to blow the dust off the kit and Wow us some More.
I see you live in BC. I have forgotten what they call across the border, here in the states it is called "Pledge With Future Shine". Basically clear lacquer for kitchen floors, brush some on where your decal needs to go and use it for adhesion. It will dry shiny so you will need to spray a dull coat over it also.
I use this method for tiny little decals and also P/E emblems on painted surfaces.