yeah funny you should say that dedman I have a lestrem kicking around in my box of tricks I also have some mounting posts for a les paul hard tail.... hmmmm I did think about it but I do like that chigsby trem style.... this guitar has been on hold for ages because I really can't make my mind up...
FYI the tail mounted chigsby doesn't work with the archtop shape its made for a flatter top and really didn't work.
I recently bought an after market roller bridge for around $9 on ebay which looks very similar to you pic.
FYI, it's a really poor design with limited range of saddle intonation which I know from wasting an hour fitting to one of my guitars. The allen key adjustment is frustrating.
I'd be relunctant to dowl up the existing bridge post holes to you know the extent of your intonation issues.