T5 Wiring Question

Hello all, I hope someone can give me some advice.

I’m planning to install a kitted T5 engine in a Vespa MY PX200 with battery and electric start. I’m fine with the mechanics of it, but will I run into problems with regards wiring?

Obviously the electric start will no longer work and I’m not bothered about that, but will I need to change anything else, will the battery still charge (horn runs off the battery) etc.

I’m hoping to just plug the existing wires running from the T5 engine into the existing loom and everything will be OK. Am I being over optimistic??!

Many Thanks

Tarquin of Tarquin