reseal / rebuild parts for a beeman guardian air rifle (aka marksman 740)

...i dunno why any one would want one of those toys to begin with - and sure cant get my head my head around wanting to rebuild it and do it again..............so i gave the dude a .177 beeman qb78 with that black tactical stock. i got it on clearance at walmart for 25 bux (impulse buy, i thought, so kept the reciept in there). i expected it to leak. then i expected it would have a super poopty chinese barrel. chronoed 650 indoors just like it was supposed to..... and it began to group after about 50 shots.......good gun for $25 !! i thought he meant that he had a beeman gs 700 (spainish norica) so i quoted him $70 for complete overhaul. but he was happy , even after a month of no replies from beemanmarksman about even the availabity of these parts (isnt it stil being sold?) less than $70 new ? ..............i called about ten times and emailed about 3 times for any sort of reply from beemanmarksman , but nothing. that was disheartening. - thanks for the help ! ..............that beeman guardian / marksman 740 air rifle is a strange bird. - paul.