I would keep your beloved tear drop.
Rubbermaid makes a 42" storage container. I figure there are other sturdy versions, but a quick search came up with this one.
http://www.homedepot.com/p/Rubbermaid-54-gal-42-1-2-in-x-21-1-2-in-x-18-3-5-in-Hi-Top-Storage-Tote-FG3A05H2MICBL/100673965and you could use a shower room such as this one
https://www.walmart.com/ip/42391766?wmlspartner=wlpa&adid=22222222227031835806&wl0=&wl1=g&wl2=c&wl3=59242041512&wl4=pla-122253653792&wl5=9009314&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=42391766&wl13=&veh=semIf your campground has a waste water disposal cistern, you could easily dispose of the used bathwater.
BTW, my 18' Shasta has a tub. I am 5' and can take a bath in it.