If that gunk in your Fujica is getting you down the Fujis are quite easy to get the lid off and get the prisms out in the main. The AZ1 is a nightmare as the prism top is totally hemmed in with electronics but most of the others are quite straightforward to do.
I neat little tip for cleaning off the top of the focus screen is apply a little bit of low tack tape - give it a few moments and then peel away - voila all of the crud is gone.
Take a look here for a sort of guide - this guys works fast and the video doesn't give many close ups but it gives you the general idea - its actually not that hard
And heres why you shouldn't even think about it with an AZ1 - it makes the guts of a Canon AE-1 look like a box brownie by comparison.