Adam ant - decreasing amperes draw can be made easy - at first, made very poor electrolyte, and test setup, looking at ampere meter. than, if you need more amperage, you can add more concentrated electrolyte (more KOH in water). at my first test i made too strong electrolyte, when i connected electrolyser to battery, huge sparks appeard, even if i connected ground as last. so, i made 2times less concentrated electrolyte, and then sparks were very small, and apmere meter shows about 30A, what soon drops to stable 25A (when electrolyte escaped from too everfilled electrolyser (screwed plates design))

Kumaran - yes, i noticed today that the black rubber gets dissolve in koh, so, there is need to find the vinyl sheets... i agree, that if screws are through plates, than it can be assembled and tightened much stronger, what is good, because of preventing leakage.
is these vinyl sheets the same, that are used as an example, in kitchens doors, or in refrigerator rooms doors, when such a doors lets easily pass through people with stuff, but stops circulating air between two rooms? it seems not easy way to find them in Latvia. but will see....