Well dutch is a bit different from german, so „doosje“ sounds much like the german word for can/tin (Dose).. So here is a thread on synthforum NL featuring some less seen Roland-Dosen™.. Of course the Roland CMU810 should be in here..
or things like this Reverb..
or did anyone see this one?..
scroll through it, you’ll find more nice „ancient gadget“ that have been forgotten or not sooo popular..