@rlx I needed to save some values in a dwg so use Ldata so could do M4=60, M6=70 and so on, save the last value for each size separately. If no value then set value to the smallest value. Like you in my dcl's can save a Button number rather than actual size.
Maybe do a defun as first step check all ldata exists and if not set to button 1.
(if (= (vlax-ldata-get "Bolts" "M4") nil)
(setq m4but 1)
)
and each pick
(vlax-ldata-put "Bolts" "M4" m4but)