Reviving an old Magellan Meridian Platinum

Hello GPS Folks. I carefully stored my old unit so was pleased to see that it started up just fine when I installed a cell. I reread my 94 page manual as some things I had forgotten. Now, after 3 days playing with it I have some questions that I cant find the answers for in the manual. First the info on my unit. In MENU, ABOUT I see the following page:
Meridian, c 2003 Thales Navigation, Rev. 4.06 Jan 23 2003 , sn: 00005982385, So based on this I assume it was made in 2003 and today is 2024 so its 22 years old.
First Question, UPDATES. The cable it comes with is to plug into the cigarrette lighter and the little power supply has the power feeder to the GPS and a data cable with a 9 pin female plug. I guess this will make it VERY hard for me to do any updates.
Second Question: The GPS gets my position very accurately so I am happy that this section is working fine but it always says 22APR05 in the date section. I guess this is due to the date roll over issues and guess I cannot do anything about this.
Third question: When I look at the screen showing the satellites in a circle after waiting until all the satellites are read I see two small w's which I assume are the WAAS extra precision signals yet nowhere does the unit say WAAS ready. Does this make any difference. Based on the precision I am achieving I am assuming that the two w's are indeed correcting as expected but just wondered.
4th question. I have been doing a lot of land surveying lately (not at the professional level) and I was contemplating buying a slightly better GPS for land measuring like the Te-Rich CM83 model. Will I achieve much more precision with this new unit or is it a waste of money and the meridian is just as precise with the WAAS?

Oh and by the way I am located in the Dominican Republic. 18degrees 26.414 min N by 69 degrees 57.343 min W

Thanks You all very much
Best Regards
John Van Allen

 

Thank you for the response.
You showed me the type of converter required for me to connect the GPS to my lap top but didn't say your opinion regarding if I might make things WORSE by trying to update. I noticed today that it is also showing the time correctly so the date issue I can live with. What do you think?

Best Regards
John

 

I guess I am sort of thinking along the line "If its working don't mess with it" and since everything else but the date is perfect I just took that attitude. Do you feel that updating the unit would be perfectly safe?

 

Ok, will do and thank you for your valued assistance. Have a nice day.

Best Regards
John Van Allen