The item is unknown but it was made in Russia, has the reference MDS61 and serial number 10470250. It is approx 11cm high and 12cm long. The other item is approx 16cm long and looks as though it fits on the side of the motor.
Originally it was suggested it was probably a boat engine but we now believe it is an aero engine - see this weblink
https://sussex-model-centre.co.uk/products/mds-61-aero-engine-side-exhaust
Aero Engine (Warminster BA12)
This offer has been gifted to someone and is no longer available.