basically, with the 048, u can expect to do the following:-
1) DW change. (pretty much a definite mod&biggest tell)
2) Lume redone. (even if u'r not a lume freak, the colour of the lume uncharged is quite a tell)
3) CG pin flatten. (definitely an issue if u get the rounded CG pin, as i've seen a mix of rounded&flushed pins on the 048)
4) CG profile. (profile of the CG may be too thin as compared to GEN, but again, have seen a mix of some with acceptable thickness.)
5) Canon Pinion mod. (most reps from that era have a recessed canon pinion, thus u'd need to mod it to have it sit flushed with the hands)
6) Dial Matte-d. (depending on the serial, i believe some GENs have matte dials or gloss dials, but this i cant comfirm)
with the above mentioned work, u might as well consider slapping a swiss movement into it to increase reliability. so even if u'r not too nitpicky, items 1,2,3&5 are pretty much needed to at least get it to look like the GEN but if u'r gona be doing so much, might as well go all the way without going franken.
u'r looking to easily fork out about the same amount as the watch to begin with. &double the amount to go all the way, again w/o going franken.
i've been waiting 2yrs for a acceptable attempt on the 048, spoken to dealers&manufacturers, none would consider taking on the project.
so yea.