Given that quantity doesn't mean quality (indeed, the former usually impairs the latter as the recent spamgate incidents have highlighted), I'd suggest an altogether more constructive way to tell if you are a smashing RBer: ladies and germs, allow me to introduce the Retrodex.
First take your post count and divide it by the number of bikes you have built and posted. This gives your Post per Bike ratio (PPBR).
Then, work out the number of months you have been a member and divide that by your PPBR. This gives you a basic index. But as we're all about quality on this site, we need to adjust for excellence.
So, for every competition you have won (BoTM, PoTM, most retro steed at an event, etc), add 0.314, which, as the astute among you will recognise, is 10% of Pi. Oh and add a piece of Pi if you organise events.
"Ein?" I hear you cry, "those words in a column are all very well, but what does it mean for me and my Retrobike status?"
Well, an avid builder who's been around a bit might have a post count of 7500, have built a dozen bikes, been on here since early 2007 and won 3 gongs. Retrodex = a stellar 1.017
A keen arriviste with 5000 posts, 1 bike, 9 months service and no prizes: Retrodex = a barely visible 0.002.
What about a steady chap with 300 posts, a couple of bikes, been here since summer 2007 and not one for competitions? Retrodex = a dull 0.273
The beauty of the retrodex is that it rewards retro bike loyalty and endeavour, not your propensity for playing word association.