Thoroughly wash cucumbers, scrubbing lightly with a soft vegetable brush removing all dirt and sand. Discard stem and blossom ends. Cut cucumbers into 1/4 inch slices. In a large stainless steel saucepan combine 1/2 cup sugar, pickling salt, mustard seed and 4 cups vinegar; bring toa a boil. Add cucumbers; boil gently 5 to 7 minutes, just until cucumbers change colour from bright to dull green. Drain cucumbers discarding cooking solution. In a separate saucepan, prepare pickling liquid - combine 3 cups sugar, allspice, celery seed and 1 2/3 cups vinegar; bring to a boil. Pack cucumbers into hot jar to within 1/2 inch of top rim. Add hot pickling liquid to cover cucumbers to within 1/4 inch of top rim (headspace). Using a nonmetallic utensil, remove air bubbles. Whipe jar rim removing any stickiness. Center snap lid on jar; apply screw band securely and firmly until resistance is met - fingertip tight. Do not overtighten. Place jar in canner; repeat for remaining jars. Cover canner; bring water to a boil. At altitudes up to 1000 ft, process - boil filled jars - 10 minutes. Remove jars without tilting. Cool upright, undisturbed for 24 hours. Do not retighten screw bands. After cooling check jar seals. Sealed lids curve downward. Remove screw bands; wipe and dry bands and jars. Store screw bands separately or replace loosely on jars as desired. Label and store jars in a cool dark place. Yield 6 pint jars or 3 quart jars.