6-Speed Gearbox 02M - Need Help!

Hello.

I'm having a problem with my transmission. It's not really a problem, but maybe someone can help me. I have a 150 hp TDI (1.9L) ARL with all-wheel drive, and the problem is that the gear ratios are too short (about 20 km/h shorter than the 115 hp PD). I want to change this. I'm planning to get the 115 hp transmission (DRW).
'I'm looking to buy one and combine its internal components with mine, specifically removing things like the shaft and transferring them to mine. My gearbox identification code is FEL. Is this possible? Do the internal parts fit? Unfortunately, the housing, especially on the engine side, is different because the transfer case is attached there. If it were the same, you could just swap the entire gearbox.'
Perhaps someone here has the parts lists for the transmission.
Anything would be helpful.

Thank you in advance.

vanblom