Dissolve gelatin mix in boiling water. Cool until slightly thickened.
Mix 3/4 graham cracker crumbs and melted butter until well blended, press into bottom of the 9 X 13 pan to form a crust. Save rest of crumbs to sprinkle on top of dessert.
Beat the Evaporated milk/heavy cream until fluffy.
In a separate bowl, beat cream cheese, sugar and lemon juice with mixer until smooth.
Add thickened gelatin and slowly mix in whipped evaporated milk.
Spread filling over the crust and sprinkle with reserved graham cracker crumbs on top.
Chill at least 2 hours and up to overnight, store covered in refrigerator.
UK/EU--digestives are a nice (and probably better) substitute for the graham cracker crumbs. This will *probably* work with your "jelly" desserts, but I cannot test since they don't sell that here. If you try it, let me know if it worked.