Amazingly (and depressingly), it doesn't actually work like most people think it does.
Under Rehabilitation of Offenders Act, depending on exactly what kind of job you're looking for you may not have to declare your convictions.
The mad thing is that your points will last longer than your documents conviction. The points will be gone in 3 years, but on your licence for 4. Your s.173 offence, although it is a relatively serious one - you presumably had it dealt with at Magistrates and got a fine. That usually means its considered spent in 6 months or a year (depending on how old you were at the time), and won't show up on a Basic DBS.
You have to be very careful exactly what you do, though. Apply for your own DBS certs and you can see exactly what will show up - but the type of job you are applying for will have a huge impact on what is and isn't disclosable. Another thing is that some DBS checks are carried out as part of particular professional memberships, rather than as a condition of employment itself - for example, locksmiths have to have DBS as part of being in the professional association, but the majority of locksmiths aren't in it.