Contesting Q plates

[Eternal]

My build is going to use a non donor engine and gearbox... but all the rest from a sierra donor (ie, dif/shafts/hubs/steering/clocks/other bits that i cant think of) Im worried that i wont be able to obtain a age related plate and thus transfer my personal plate (birthday gift) to the car when its all done im only going to build one of these so want it done right. I remember seeing a points system somewhere but i just dont think i will have enough parts to be able to get away with it. my questions are....

1) has anyone got a age related plate with a non donor engine/gearbox

2) how hard is it to contest (in a non violent way) a Q plate

The other option is to build the chassis to fit a skyline engine then install a cvh and mt75 from a donor get it all up and running then rebuild it all again.

Any help and advice welcome!