engine rebuilt and running

[skipoman]

Hi.Can anyone help me. I have a mk8 2.2 rwd . I got the engine running today after a full rebuild incl rear crank oil seal. Runs lovely.No leaks around engine anywhere now. I have noticed there is oil between bell housing and gearbox . (very small leak on floor). Its either front oil seal on gearbox or is the slave cylinder or thrust bearing incorporated into an oil seal? The previous engine had a broken lower sump pan by bell housing so was leaking engine oil previously I believe. The lower sump pan was fitted flush and all parts cleaned very well.I did clean up inside bellhousing when it was apart.
I also topped up gearbox level by quite a bit. So at moment cant distinguish weather its engine or gearbox oil but after all the work Ive done has to be front of gearbox knowing that I topped it up to.
Yes could be rear crank oil seal but I want to know how the oil is retained in the gearbox first.I will use van for a while to work out if its engine oil loss . Any thoughts would be helpful.

[ME]

Not much help, but usually you can smell, or dare I say taste the difference in most vehicle related fluids.

[skipoman]

Sorry maybe I havent been very clear.Yes pretty sure its gearbox but just want to no what holds the gearbox fluid in the bell housing end. (input end). Oil seal or something else?
I can order part before hand then.