Originally Posted by Roelof

OK, let me explain....

Most (older) Novarossi (based) models have a bore/stroke of 16.2 x 16.8, all use the same R rod except some special models with a C, P, E or O rod like the 359 and the Collari Cordoba edition. The R rod comes in different versions but are exchangeable.

Some R7 rods have a green surface on the brass bushing, basically it is a kind of oxidize layer. (bras colors green like iron colors brouwn and aluminium colors white)

All onroad sleeves I have seen with this bore/strok specs have a 19.5mm sleeve but most 9 port sleeves have a 3mm thick upper lip and most 7 port and less a 2mm upper lip. Depending the size of that upper lip there are also different length of the combustion chambers.

But there are flat pistons, domed pistons and pistons with a different offset of the piston pin. And with that the portheight can be different. With some sleeves the portheigt is set in the sleeve and with some it seems it is set with how deep the sleeve will go into the crank cace.

In the early days all engines were made by a same design/dimensions and it was easy to exchange parts but now with the different offsets and pistons. it is a question if it will fit.
If you know how to raise or lower the sleeve you can fit them all but it is not easy to tell which different P/S set is a direct fit.