Z1-R Front Caliper Repair Kits - Boots too Big

Got a couple of caliper repair kits from Z1Enterprises (P/N 32-1289) to fit to my '78 Z1-R but found that the dust boot doesn't fit the outer rim of the 38mm piston no how much "persuasion!" The groove is too skinny and the inner and outer dimensions of the boot groove are too large for the piston. Anyone have a similar problem and have a solution? Attached is a pic of the piston and boot with measurements. (The piston seal is 50mm and you need to order the 45 mm one ,per Z1 Enterprises website recommendations, for a Z1-R)

Attached is a pic of the piston with seal and dust boot measurements.

Problem solved - operator headspace eror! (this idiot was trying to fit the piston into the boot instead of the boot onto the piston - Duuuh-ohh!) Have now got all the parts for the front brake rebuild - hope to post a pic of the updated rolling chassis next week.